黄砂、干土不能用来扑救下面哪种火灾?
A、甲类火
B、电器火
C、金属火
D、爆炸品火灾
参考答案:D
97. You’d better stay at school now. Look! The sky is overcast with dark clouds. I’m afraid _____ rain is going to fall.
A.large
B.big
C.great
D.Heavy
选择毛细管柱时应考虑的因素有()。
A、柱内径
B、柱长
C、液膜厚度
D、材料