在紧急情况下，蜥蜴的尾巴能自动断落，断落部分还能做屈曲运动，蜥蜴的这种行为是动物的[ ]
A．攻击行为
B．繁殖行为
C．社群行为
D．防御行为
答案：D
构造柱和圈梁的设置主要是为了（）。
A.提高建筑物整体性，抵抗地震力
B.承受竖向荷载
C.便于砌筑墙体
D.建筑构造的需要
用所给词的正确形式填空
1. Every year a lot of _____(visit) come to China.
2. He _____(meet) a friend on the street yesterday.
3. This song _____(sound) beautiful.
4. I'm _____(terrible) sorry. I can't go fishing with you this weekend.
5. He won the first prize, He was the _____(win).
