恒定表面浓度的条件下,在整个扩散期间,()保持恒定表面浓度。
A.源蒸气
B.杂质和惰性气体混合物
C.水蒸气和杂志混合物
D.杂质、惰性气体、水蒸气混合物
参考答案:A
Lee MinHo, _____ music and films are loved by many teenagers, was invited to perform in the 2014 Spring Festival.
A.who
B.whom
C.whose
D.which
驾驶员发现装车的货物有下列()情况的,不得起运。
A.未按规定包装
B.包装破损
C.有潮湿现象
D.有发热现象