It’s really difficult to ______ what he is trying to express.[ ]

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。

In much of the animal world, night is the time ____ for sleep —pure and simple.

How many handbags did you buy yesterday— ________. They are too expensive.

Having heard the touching stories of “the most beautiful teacher”, she ____tears .