冒顶区的正常通风一时不能恢复,则必须利用()向埋压或截堵的人员供给新鲜空气。
A.压风管
B.水管
C.打钻
D.作巷道
参考答案:A, B, C
The happy student was singing ____ he was going home.[ ]
A. until
B. as
C. since
D. and
最易与Coats病发生混淆的是()
A.内生性Rb
B.外生性Rb
C.多灶性Rb
D.弥漫浸润性Rb
E.转移性Rb