another problem

steven.wei

The National Transportation Safety Board has recommended the use of fail-safe mechanisms on airliner cargo door latches assuring the doors are properly closed before takeoff and to prevent them from popping open in flight.
(A)        assuring the doors are properly closed
(B)        for the assurance of proper closing
(C)        assuring proper closure
(D)        to assure closing the doors properly
(E)        to assure that the doors are properly closed

DE二者的本质区别在哪里？当年老白好像以什么固定用法区别二者，现在想起来有点那个。请高手帮助，先谢了。

Louisa_xy

assure sth.
assure sb.of sth.
assure that...

steven.wei

to Louisa_xy

我又查了一下OG，还是有点有明白，再请教一二。
OG中的原文关于D。E的解释如下：
D offers the necessary infinitive, but the gerund phrase closing ... imprecisely refers to the act of closing the doors rather than to the condition of the closed doors.
它这里的condition指什么，难道表动作gerund phrase就真的不行？

Louisa_xy

assure closing the doors properly确保closing the doors这个动作
assure that the doors are properly closed 确保门关的正确这一状况
体会..

steven.wei

3ks a lots.....