不属于“道光萧条”发生的背景是()。
A.国力衰弱
B.农业生产不景气
C.战乱频繁
D.财政拮据
参考答案:C
One of the differences between the Pacific Ocean and the Indian Ocean is that the former has______waves.
A.largest
B.large
C.larger
D.the largest
Rf值最大等于1,即该组分随展开剂上升至(),表示溶质不进入固定相。
A.溶液上面
B.溶剂前缘
C.溶质前缘
D.溶剂下面