单选题
（3.2）刚架的剪力图如（ ）所示（5分）
单选题
桁架各杆的轴力如（ ）所示（10分）
单选题
（5.1）1杆的轴力FN1=（ ）所示（3分）
单选题
（5.2）2杆的轴力FN2=（ ）所示（3分）
单选题
（5.3）3杆的轴力FN3=（ ）所示（4分）
单选题
（6.1）简支梁A端的角位移为（ ）（5分）
单选题
（6.2）简支梁跨中C点的竖向位移为（ ） （5分）
单选题
悬臂刚架D点的竖向位移为（ ）（10分）
单选题
What are the definitions of the two main types of families?
The nuclear family consists of two parents and their biological or adopted children.
The extended family may include grandparents, parents, children and relatives living together on the same street or in the same area.
Human beings lived in loosely-related groups. Each group had a common ancestor long time ago.
The nuclear family is the same as the extended family.
单选题
What are the reasons for the changes in the structure of the family?
In the early 1900s in the United States, the divorce rated went down and the birthrate went down.
At that time, couples were staying married for few years.
The divorce rate went down and the birthrate began to rise in the early 1900s in the United States.
Couples did not want many children then.