火灾报警器包括:火灾()等。
A.挥手报警
B.声音报警器
C.光控报警器
D.大叫报警
参考答案:B, C
画局部剖视图时,用做视图与局部剖视的分界线应采用()
A、波浪线
B、双折线
C、A或B均可
D、双点画线
The singer and the dancer ____ come to the meeting. [ ]
A. has
B. have
C. are
D. is