放空管出口应在远离明火作业的安全地区。若室内放空管出口近屋顶,应高出屋顶()m以上。
A.1
B.2
C.3
D.4
参考答案:B
I was watching the news on TV ________ the power went off.
A.when
B.as
C.while
D.until .
(1)图1中木块的长度是是______cm。
(2)图2中温度计的示数是______℃。
(3)图3中测力计的示数是______N。