将下列句子组成一个语段,顺序恰当的一项是(　　)①语段,又叫句群,是由句子组成的语言表达单位。②它是建筑在逻辑思维基础上的表意“层次”。③语段正是这样一个相对独立的较大语义单位。④但是,要表达多方面的、比较复杂的思想,往往需要把几个句子组织起来,结成更大的言语片段,以表达“一层”的意思。⑤我们知道,句子在一定的语言环境中能够单独地使用,能够单独地表达相对完整的思想。⑥它是句子和语篇之间的中间层次。

Mary knows so much about ______earth! —Yes, although she is only ____eight- year-old girl.

How far apart do they live?—________I know, they live in the same neighbourhood.[ ]

such circumstances, it is little ________ thatthey experience difficulties.

He to get a high position in the company, but failed because of his carelessness.