单选题
（1.3）将临界力和由强度条件得到的许用压力比较，可知（ ）（2分）
压杆会失稳破坏
压杆稳定
单选题
（2.1）由欧拉公式可求得压杆的临界力为（ ）（4分）
3.7kN
1.5kN
6.4kN
1.414kN
单选题
（2.2）当截面改成b=h=30mm，保持杆长不变，压杆的临界力为（ ）（4分）
8.33kN
6.65kN
4.7kN
24.8kN
单选题
（2.3）若截面面积与杆件长度保持不变，截面形状改为圆形，压杆的临界力为（ ）（2分）
7.95kN
10.05kN
6.82kN
11.6kN
匹配题
Match each vocabulary word on the left with the correct definition on the right. (0.4 points each)
make sense
- to be reasonable or necessary
pedestrians
- people traveling on foot, walking
vehicle
- something like a car or truck used to transport people
teenager
- a person over 12 and under 20 years old
fine
- money to be paid as a punishment
单选题
make sense
- to be reasonable or necessary
单选题
pedestrians
- people traveling on foot, walking
单选题
vehicle
- something like a car or truck used to transport people
单选题
teenager
- a person over 12 and under 20 years old
单选题
fine
- money to be paid as a punishment