The young couple couldn’t afford a new house. ____,they wouldn’t have bought an old one.

Day, President Hu Jintao demanded that the problems _________ paid specialattention to

There are a lot of _________ of bike riding.—I agree. It’s good for the environment and it saves money.

The research on the new flu virus vaccine ischallenging and demanding Who do you think can do the job —_______ my students have a try

填入下面一段文字横线处的语句，最恰当的一句是荷花能“出污泥而不染”，荷叶可将水滴抖落得干干净净，这是因为其外表覆盖着一种像蜡一样的物质，科学家们称这种表面为“拒水表面”。荷叶的拒水表面上布满“小包”，它们紧紧地挨在一起，形成了一个针对于叶面的“保护层”。你可以将那些“小包”想象成无数撑开的“雨伞”， “雨伞”的下面形成了一层极薄的“气垫”。当雨滴落下时，“气垫”中的空气并没有排出去。由于“小包”间的距离非常小，________ ，雨水便只能在“小包”上面滚来滚去了。