试炭膜乱寝峰赌餐估曙筐纲伦
1. Introduction
Quiz – Classification of Supports
1、判断题：
Are reactions shown in the figure correct?
A: 正确
B: 错误
答案: 错误
2.Geometric Construction Analysis
2,1 Quiz
1、判断题：
The geometrically variable system cannot in equilibrium under any load.
A: 正确
B: 错误
答案: 错误
2、判断题：
A rigid body can be a rod or a geometrically invariant system composed of several rigid plates.
A: 正确
B: 错误
答案: 正确
2.2 Quiz
1、判断题：
The degree of freedom of a geometrically invariant system must be equal to zero.
A: 正确
B: 错误
答案: 错误
2、判断题：
A system with redundant constraints must be geometrically invariant.
A: 正确
B: 错误
答案: 错误
2.3 Quiz
1、单选题：
Three rigid plates connected by three hinges are:
A: Stable
B: Unstable
C: Instantaneously unstable
D: Stable, unstable, or instantaneously unstable
答案: Stable, unstable, or instantaneously unstable
2、判断题：
If the three rigid plates are connected by three single hinges or any six links, the system must be geometrically invariant.
A: 正确
B: 错误
答案: 错误
3、判断题：
If three rigid plates are connected by three virtual hinges, which are not on the same straight line, the system is geometrically invariant without redundant constraints.
A: 正确
B: 错误
答案: 正确
4、判断题：
According to the rule of three rigid plates, the three hinges are collinear, so it is an instantaneously unstable system.
A: 正确
B: 错误
答案: 错误
5、判断题：
The motion produced by the instantaneously unstable system is very small and quickly transformed into a geometric invariant system, so it can be used as an engineering structure.
A: 正确
B: 错误
答案: 错误
2.4 Quiz
1、单选题：
The system is composed of two rigid plates connected by three links. It is:
A: Unstable
B: Stable
C: Instantaneously unstable
D: Stable, unstable, or instantaneously unstable
答案: Stable, unstable, or instantaneously unstable
2、判断题：
Two rigid plates connected by three links at one point form a geometrically invariant system.
A: 正确
B: 错误
答案: 错误
3、判断题：
The structure is an unstable structure..
A: 正确
B: 错误
答案: 错误
4、判断题：
The structure shown below is a stable structure.
A: 正确
B: 错误
答案: 错误
5、判断题：
The connecting point O between link 1 and link 2 is a virtual hinge.
A: 正确
B: 错误
答案: 错误
2.5 Quiz
1、单选题：
The structure shown below is：
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
2、判断题：
The following structural system is unstable.
A: 正确
B: 错误
答案: 错误
2.7 Quiz
1、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Instantaneously unstable
C: Unstable
D: Stable with redundant restraint(s)
答案: Stable without redundant restraint
2、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Instantaneously unstable
C: Unstable
D: Stable with redundant restraint(s)
答案: Instantaneously unstable
3、判断题：
In the rule that two or three rigid bodies constitute a geometrically invariant system, not only the number of necessary constraints, but also the conditions that these constraints must satisfy are specified.
A: 正确
B: 错误
答案: 正确
4、判断题：
In the system shown in the figure, after removing 1-5, 3-5, 4-5, 2-5 and four links, the simply supported beam 12 is obtained, so the system is a stable system with four redundant constraints.
A: 正确
B: 错误
答案: 错误
5、判断题：
Some systems can be unstable but with redundant constraints.
A: 正确
B: 错误
答案: 正确
6、判断题：
The three basic rules of plane geometric invariant system are relatled with each other.
A: 正确
B: 错误
答案: 正确
7、判断题：
The planar system shown in the figure is an instantaneously unstable system because a, B and C are collinear.
A: 正确
B: 错误
答案: 错误
8、判断题：
In the figure below, AC and BC form a binary system. If it is removed in the geometric composition analysis, the remaining part is an unstable system. So the original system is also an unstable system.
A: 正确
B: 错误
答案: 错误
9、判断题：
A system with redundant constraints must be geometrically invariant.
A: 正确
B: 错误
答案: 错误
10、判断题：
In the rule that two or three rigid plates constitute a geometrically invariant system, not only the number of necessary constraints, but also the geometric conditions that these constraints must satisfy are specified.
A: 正确
B: 错误
答案: 正确
Unit test 1
1、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable with redundant restraint(s)
2、单选题：
The following structural system is:
A: Unstable
B: Instantaneously unstable
C: Stable without redundant restraint
D: Stable with redundant restraint(s)
答案: Stable without redundant restraint
3、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable with redundant restraint(s)
4、单选题：
The structural system shall be designed to be:
A: Stable
B: Unstable
C: Instantaneously unstable
D: Stable or instantaneously unstable
答案: Stable
5、单选题：
The following structural system has three redundant restraints. To ensure that it is still stable, which two restraints cannot be removed at the same time?
A: a and e
B: a and b
C: a and c
D: c and e
答案: a and b
6、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Instantaneously unstable
7、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
8、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Unstable
9、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable with redundant restraint(s)
10、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable without redundant restraint
11、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
12、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Unstable
13、单选题：
The following structural system is:
A: Unstable
B: Instantaneously unstable
C: Stable without redundant restraint
D: Stable with redundant restraint(s)
答案: Stable without redundant restraint
14、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable with redundant restraint(s)
15、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
16、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Instantaneously unstable
17、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable with redundant restraint(s)
18、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable with redundant restraint(s)
19、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Instantaneously unstable
20、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable with redundant restraint(s)
21、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable with redundant restraint(s)
D: Instantaneously unstable with redundant restraint(s)
答案: Unstable with redundant restraint(s)
22、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Instantaneously unstable
23、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable with redundant restraint(s)
24、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Instantaneously unstable
25、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable without redundant restraint
26、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Instantaneously unstable
D: Unstable
答案: Stable with redundant restraint(s)
27、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable with redundant restraint(s)
28、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
29、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with redundant restraint(s)
C: Unstable
D: Instantaneously unstable
答案: Stable without redundant restraint
30、单选题：
The following structural system is:
A: Stable without redundant restraint
B: Stable with one redundant restraint
C: Instantaneously unstable
D: Stable with two redundant restraints
答案: Stable with one redundant restraint
3. Statically Determinate Structures
3.1 Quiz
1、单选题：
The geometric characteristics of statically determinate structures are:
A: No redundant restraint(s)
B: Stable
C: The degree of freedom is zero
D: Stable with no redundant restraint(s)
答案: Stable with no redundant restraint(s)
2、单选题：
As shown in the figure, the reaction force at support A (upward is positive) is:
A: －P
B: －2P/3
C: －P/3
D: 0
答案: 0
3、单选题：
The vertical reaction of support C in the arch is:
A: P (upward)
B: P (downward)
C: 2.5P (upward)
D: P/2 (upward)
答案: 2.5P (upward)
4、单选题：
As shown in the figure, the vertical reaction of the left support of the hinged arch is:
A: 0
B: 1kN
C: 2kN
D: 3kN
答案: 0
5、单选题：
Under the action of load, which of the following is true for reactions and internal forces of statically determinate structure?
A: It is not only determined by equilibrium condition, but also by deflection condition
B: It can be obtained by static equilibrium condition, but sometimes the value is uncertain
C: In special cases, it can be uniquely determined by the static equilibrium condition
D: All of them can be obtained by static equilibrium condition, and the numerical value can be determined.
答案: All of them can be obtained by static equilibrium condition, and the numerical value can be determined.
6、判断题：
All the internal forces and reactions of statically determinate structures are obtained only according to the equilibrium conditions, and the solution is unique.
A: 正确
B: 错误
答案: 正确
7、判断题：
Geometrically invariant systems must be statically determinate.
A: 正确
B: 错误
答案: 错误
8、判断题：
The “uniqueness of solution” of statically determined structure refers to that the reaction force, internal force and deformation are determined by static equilibrium conditions only.
A: 正确
B: 错误
答案: 错误
3.10 Quiz
1、单选题：
In the truss shown in the figure, the axial forces of members 1 and 2 are:
A: 
B: 
C: 
D: 
答案:
2、单选题：
The internal force of member AB shown in the figure is:
A: 2P
B: 
C: 
D: 0
答案: 0
3、单选题：
In the truss shown in the figure, the axial forces of members 1 and 2 are:
A: 0.25P，0.75P
B: 0.75P，1.414P
C: 0，1.06P
D: 0，-0.75P
答案: 0，1.06P
4、单选题：
In the truss shown in the figure, the correct internal forces of members 1 and 2 are:
A: 
B: 
C: 
D: 
答案:
5、单选题：
The internal force of member b is:
A: hP/2d
B: hP/3d
C: 0
D: P/2
答案: 0
6、单选题：
As shown in the figure, the change of the internal force of the lower chord of the truss is:
A: Small at both ends, large in the middle
B: Large at both ends, small in the middle
C: The internal force of each member is the same
D: The change has no rule to follow
答案: Small at both ends, large in the middle
7、判断题：
The internal force of member AB bar the structure 5Pd/(2h).
A: 正确
B: 错误
答案: 错误
8、判断题：
The internal force of member A shown in the figure is —P.
A: 正确
B: 错误
答案: 错误
3.11 Quiz
1、单选题：
How many members with zero force are there in the structure below?
A: 3
B: 6
C: 8
D: 7
答案: 8
2、单选题：
The internal forces of members 1, 2 and 3 shown in the figure are:
A: 
B: 
C: 
D: 
答案:
3、判断题：
The truss shown here has 9 zero force members.
A: 正确
B: 错误
答案: 正确
4、判断题：
The internal force of member 1 is zero.
A: 正确
B: 错误
答案: 正确
5、判断题：
The truss shown in the figure has three zero force members.
A: 正确
B: 错误
答案: 错误
6、判断题：
图示结构A杆的内力为P/2。
A: 正确
B: 错误
答案: 正确
7、判断题：
The internal forces in members 1 and 2 are FN1=-FN2=P.
A: 正确
B: 错误
答案: 错误
8、判断题：
The internal force of member a is 1.4142P.
A: 正确
B: 错误
答案: 错误
3.12 Quiz
1、单选题：
The axial force of member 1 is:
A: 0
B: -P
C: P
D: -P/2
答案: -P/2
2、单选题：
In the structure shown in the figure, the internal force of the section on the right side of point A on the beam type member is:
A: 
B: 
C: 
D: 
答案:
3、单选题：
In the structure shown in the figure, the internal force of member a is:
A: P
B: －3P
C: 2P
D: 0
答案: 2P
4、判断题：
In the composite structure, the internal force of chain bar (truss type member) is axial force, and the internal force of beam type member is only bending moment and shear force.
A: 正确
B: 错误
答案: 错误
5、判断题：
The axial force of member AB is P (tension).
A: 正确
B: 错误
答案: 错误
6、判断题：
In the structure shown in the figure, if the reaction force of support is known, the axial force of member CD can be obtained from the equilibrium condition of joint D.
A: 正确
B: 错误
答案: 错误
7、判断题：
In the structure shown in the figure, members AC and CB do not generate bending moment.
A: 正确
B: 错误
答案: 错误
8、判断题：
As shown in the figure, the axial force of member DE is 30 kN under the action of load.
A: 正确
B: 错误
答案: 错误
9、判断题：
As shown in the figure, the axial force of member 1 is 0.
A: 正确
B: 错误
答案: 正确
10、判断题：
In the structure shown in the figure, the internal forces of all two-force bars are zero.
A: 正确
B: 错误
答案: 正确
11、判断题：
The bending moment of section A is 40 kN-m (counterclockwise).
A: 正确
B: 错误
答案: 错误
3.2 Quiz
1、单选题：
The shape of the moment diagram shown in the diagram is:
A: Correct
B: Wrong
C: Part of it is wrong
D: It is correct under certain conditions
答案: It is correct under certain conditions
2、判断题：
The bending moment diagram shown in the figure is correct. （ ）
A: 正确
B: 错误
答案: 错误
3、判断题：
When the same simply supported inclined beam is subjected to two kinds of distributed loads with different forms but equal value, their bending moment diagrams are the same. ( )
A: 正确
B: 错误
答案: 错误
3.3 Quiz
1、单选题：
The section where the bending moment diagram has abrupt change is: ()
A: Section with concentrated load
B: Section with zero shear force
C: Section with zero load
D: Section with concentrated couple
答案: Section with concentrated couple
2、判断题：
The bending moment of AB in the structure shown in the figure is constant.
A: 正确
B: 错误
答案: 正确
3、判断题：
The M diagram of the structure in Fig. A is shown in Fig. B.
A: 正确
B: 错误
答案: 正确
4、判断题：
The internal force of AB is zero.
A: 正确
B: 错误
答案: 正确
3.4 Quiz
1、单选题：
As shown in the figure, the bending moment of the midspan section of AB beam is:
A: 10 kN-m, tension on the top
B: 10 kN-m, tension at bottom
C: 20 kN-m, tension on the top
D: 20 kN-m, tension at bottom
答案: 10 kN-m, tension at bottom
2、单选题：
The moment at section D for the beam shown below is:
A: 20 kN-m (top is subjected to tension)
B: 18 kN-m (bottom is subjected to tension)
C: 18 kN-m (top is subjected to tension)
D: 20 kN-m (bottom is subjected to tension)
答案: 18 kN-m (bottom is subjected to tension)
3、判断题：
The superposition of two bending moment diagrams does not refer to the simple combination of the figures, but refers to the superposition of the bending moment ordinates corresponding to the two diagrams.
A: 正确
B: 错误
答案: 正确
4、判断题：
The following figure shows the M diagram of the beam.
A: 正确
B: 错误
答案: 错误
5、判断题：
Is the bending moment diagram of the structure shown in the figure below correct?
A: 正确
B: 错误
答案: 正确
3.6 Quiz
1、单选题：
How will the load load acting on the fundamental part of the static multi-span beam on the subsidiary part?
A: Absolutely no internal force
B: Generally, it does not genearte internal force
C: It usually generates internal forces
D: It will generate internal force
答案: Absolutely no internal force
2、单选题：
As shown in the figure, the bending moment of section C of multi-span statically determinate beam is equal to:
A: Pl（top is subjected to tension)
B: Pl（bottom is subjected to tension)
C: Pl/2（top is subjected to tension)
D: Pl/2（bottom is subjected to tension)
答案: Pl/2（bottom is subjected to tension)
3、单选题：
As shown in the figure, the bending moment of section K is:
A: 5kN·m
B: 9kN·m
C: 13kN·m
D: 6kN·m
答案: 5kN·m
4、判断题：
When the load acts on the subsidiary part of the statically determinate multi-span beam, the internal force of the fundamental part is not zero.
A: 正确
B: 错误
答案: 正确
5、判断题：
When the external load acts on the fundamental part, the subsidiary part is not taking the load; when the external load acts on a certain subsidiary part, the whole structure must take the load.
A: 正确
B: 错误
答案: 错误
6、判断题：
The diagram shows the statically determinate structure. Under the action of horizontal load, AB is the fundametal part and BC is the subsidiary part.
A: 正确
B: 错误
答案: 正确
7、判断题：
The diagram shows a statically determinate structure. Under the action of vertical load, AB is the fundamental part and BC is the subsidiary part.
A: 正确
B: 错误
答案: 错误
8、判断题：
As shown in the figure, the load P on the beam will generate internal force in CD.
A: 正确
B: 错误
答案: 错误
9、判断题：
The shape of the bending moment diagram shown in the figure is correct.
A: 正确
B: 错误
答案: 错误
3.7 Quiz
1、单选题：
In the structure shown in the figure, which one is correct for the E-end bending moment of member EG and the shear force of B-section of member BA?
A: (M)EG=16 kN-m (upper side is subjected to tension), (Fs)BA=8 kN
B: (M)EG=16 kN-m (lower side is subjected to tension), (Fs)BA=8 kN
C: (M)EG=16 kN-m (lower side is subjected to tension), (Fs)BA=-8 kN
D: 
(M)EG=16 kN-m (upper side is subjected to tension), (Fs)BA=16 kN
答案: (M)EG=16 kN-m (lower side is subjected to tension), (Fs)BA=8 kN
2、单选题：
As shown in the figure, the bending moment at C-end of CD in the rigid frame is:
A: 0
B: -Pl (top is subjected to tension）
C: Pl ((bottom is subjected to tension）
D: -2Pl (top is subjected to tension）
答案: 0
3、单选题：
As shown in the figure, the bending moment at B-end of member BA is (assuming the left side subjected to tension is positive) is:
A: 2Pa
B: Pa
C: 3Pa
D: -3Pa
答案: 3Pa
4、单选题：
According to the structure shown in the figure, the bending moment at D-end of member DC is (assuming that the lower side subjected to tension is positive):
A: －Pa
B: Pa
C: －Pa /2
D: Pa /2
答案: －Pa /2
5、单选题：
Which of the following is correct for both MAC and MBD?
A: MAC=Ph (left side is subjected to tension); MBD=Ph (left side is subjected to tension)
B: MAC=Ph (left side is subjected to tension); MBD=0
C: MAC=0; MBD=Ph (left side is subjected to tension)
D: MAC=Ph/3 (left side is subjected to tension); MBD=2Ph/3 (left side is subjected to tension)
答案: MAC=0; MBD=Ph (left side is subjected to tension)
6、单选题：
In the static rigid frame shown in the figure, the bending moment of section A of AB is:
A: 2Pa (left side is subjected to tension）
B: Pa (left side is subjected to tension）
C: 0
D: Pa（right side is subjected to tension）
答案: Pa (left side is subjected to tension）
7、判断题：
For the structure below, the moment at B end of member BC MBC=ql^2/2 (positive is bottom is subjected to tension).
A: 正确
B: 错误
答案: 错误
8、判断题：
For the structure below, Mk=ql^2/2 (inside is subjected to tension).
A: 正确
B: 错误
答案: 错误
9、判断题：
The moment diagram is correct.
A: 正确
B: 错误
答案: 错误
3.9 Quiz
1、单选题：
As shown in the figure, the horizontal thrust at the support of three hinged arch is:
A: 30 kN
B: 20 kN
C: 10 kN
D: 40 kN
答案: 20 kN
2、单选题：
In the three-hinged arch shown below, if the horizontal thrust H = P / 3, the height to span ratio f / l should be equal to:
A: 3/8
B: 1/2
C: 5/8
D: 3/4
答案: 3/8
3、判断题：
The reason why the bending moment of the three hinged arch is less than that of the corresponding simply supported beam is that there is horizontal support reaction.
A: 正确
B: 错误
答案: 正确
4、判断题：
Under the same span and vertical load, the horizontal thrust of three-hinged arch with the same height of arch foot decreases with the decrease of rise.
A: 正确
B: 错误
答案: 错误
5、判断题：
The three hinged arch designed according to the rational arch axis can make the bending moment of each section in the arch zero under any load.
A: 正确
B: 错误
答案: 错误
6、判断题：
In the structure below, the vertical support reactions are FAy=m/l (up), FBy=m/l (down).
A: 正确
B: 错误
答案: 错误
7、判断题：
The horizontal thrust of the arch shown below is 3ql/4.
A: 正确
B: 错误
答案: 正确
8、判断题：
The moment of K section of the arch below (M)=ql^2/32 (lower side is subjected to tension).
A: 正确
B: 错误
答案: 错误
9、判断题：
The system shown in the figure is arch structure.
A: 正确
B: 错误
答案: 错误
Unit test 2
1、单选题：
The reactions at support A are
A: 
B: 
C: 
D: 
答案:
2、单选题：
The moment at section C is：
A: 
B: 
C: 
D: 0
答案: 0
3、单选题：
The moment at joint B is：
A: Outside is subjected to tension
B: Inside is subject to tension
C: The value is zero
D: All above three options are possible.
答案: All above three options are possible.
4、单选题：
In the following structure:
A: 
B: 
, outside is subjected to tension
C: 
inside is subjected to tension
D: 
答案:
5、单选题：
In the following structure, moment at sections A and C are (assume that it is positive when the bottom is subjected to tension):
A: 
B: 
C: 
D: 
答案:
6、单选题：
Internal forces in a determinate structure are:
A: not related to the structure’s EI
B: related to the structure’s relative EI
C: related to the structure’s absolute value of EI
D: related the structure I, but not E
答案: not related to the structure’s EI
7、单选题：
Moment at section C for the multi-span determinate beam shown below is:
A: Pl (top is subjected to tension)
B: Pl (bottom is subjected to tension)
C: Pl/2 (top is subjected to tension)
D: Pl/2 (bottom is subjected to tension)
答案: Pl/2 (bottom is subjected to tension)
8、单选题：
The shear at section below K for the structure shown below is:
A: 0
B: -P
C: P
D: P/2
答案: 0
9、单选题：
What will forces acting on fundamental parts do to the subsidiary portions?
A: Definitely will not generate internal forces
B: Generally will not generate internal forces
C: Generally will generate internal forces
D: Definitely will generate internal forces
答案: Definitely will not generate internal forces
10、单选题：
Moment at section K for the structure shown below is (assume that it is positive then the bottom is subjected to tension):
A: 
B: 
C: 
D: 
答案:
11、单选题：
Shear at section A for the structure shown below is:
A: -P
B: P
C: P/2
D: -P/2
答案: -P/2
12、单选题：
Moment at section C in member CA and shear at section C in member CB for the structure shown below are:
A: 
B: 
(left side is subjected to tension),
;
C: 
D: 
(left side is subjected to tension),