You can borrow this useful book from the library .

　　你可以从图书馆借到这种有用的书。

　　A more suitable person than him for the job can not be found . 不可能找到比他更适合这份工作的人了。

　　Now people can skate on the lake .现在人们可以在湖上滑冰了。

　　When the storm stopped , the plane could take off .

　　当风暴停下来时，飞机可以起飞了不得。