Look! The ground is wet. It must have rained last night, ________？

A．hasn't it

B．hadn't it

C．mustn't it

D．didn't it

汶川地震后，同学们纷纷伸出援助之手，用自己平时积攒的零用钱买学习用品捐送给灾区的同龄人。这是同学们对自己合法财产行使(    )。

A．使用权

B．占有权

C．处分权

D．收益权