A:左视图与俯视图相同
B:左视图与主视图相同
C:主视图与俯视图相同
D:三种视图都相同
∠A=____
∠C=____
∠A=∠B=____
城市人口迅速增加会产生( )
It is dangerous for teenagers to give out too much about themselves on the Internet.