放炮前生对工作面范围内巷道周边进行冲洗，不得有厚度超过（）mm，连续长度超过（）m的粉（煤）尘堆积。
A、2，5
B、2，3
C、1，4
参考答案：A
Toddy couldn’t clearly remember the exact date of the bus accident, but he knew it was______ Sunday because everybody was at _______church．
A．不填；the
B．the；不填
C．不填；a
D．a；不填
The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.
A．that
B．it
C．this
D．him
