— Was the driving pleasant when you went to Mexico last summer?

— No, it ＿＿ for four days when we arrived, so the roads were very muddy.

A．was raining

B．had been raining

C．would be raining

D．rained

下列观点不符合比较优势论的是（）

A.国际分工的基础是各国存在的劳动生产率的绝对差别

B.一国应集中生产优势最大的产品

C.劳动生产率差异的原因是历史条件和自然条件

D.各国应出口具有比较优势的产品