下列几何图形中,一定是轴对称图形的有( )
A:2个
B:3个
C:4个
D:5个
A. Let me see. I think it's a toilet for a pet(宠物).
B. Yes. I do. I like studying them.
C. Do you know anything about the public signs?
D. OK. What does that sign on the door mean?
下列有关文学常识的表述,错误的一项是( )
如图为突触的亚显微结构的示意图,A、B分别表示两个神经元的局部结构,下列相关的叙述中正确的是( )
The doctor has devoted most of his time to the patients.