硝化棉应存于()中,以免这些易燃固体物品暴露于空气中发生自燃,有的急速氧化产生热和可燃气体等。
A.水
B.乙醇
C.煤油
D.柴油
参考答案:B
买断式回购的完整合同应包括买断式回购主协议、回购合同和补充协议。( )
With a lot of homework _________, I had to stay at home all day.
A.done
B.doing
C.to do
D.being done