依次填入下面一段文字横线处的语句，衔接最恰当的一项是（ ）_________ 但是对于它们的全体容貌，恐怕始终没有看清楚呢。因为这必须隔着相当的距离方才看见。唐人诗云：“山远始为容。”我以为树亦如此。①但在形式上是我所有的。②这些都是邻家院子里的东西，③寓楼的窗前有好几株梧桐树。④因为它们和我隔着适当的距离，⑤它们的主人，对于它们的局部状态也许比我看得清楚。⑥好像是专门种给我看的。

It’s difficult for him to fulfill such a task within limited time, but not ________ impossible [ ]

Could you please give some _______ to the _______ teachers

.People have planted a great many trees in order to _____ wind and sand in the desert.

They were walking around the town _______ a place for the party