Once the fire fighters had come to George's rescue George had his arm greased and was able to get it out of the drain.

对这个句子有几个问题,请老师帮忙解答一下

1. come to George's rescue 这种 （乔治的救援..）是什么用法，为什么把动词当名词来用？

【答】这里，rescue 原本就是名词，带有动词性质。词组 George's rescue：rescue 跟 George 是“动宾关系”，或者说“乔治与救援是被动关系”。即：“乔治被救援”。又如：

When I heard that he was in trouble, I came to his help at once.

当我听说他有麻烦的时候，我立刻就来帮助他了。（他被我帮助）

2. George had his arm greased 和 George greased his arm 意思完全相等吗？ 

【答】原本就不相等，哪来的“完全相等”？前者“别人给乔治抹上润滑油”，后者是“乔治自己抹上润滑油”。

3. 如果要体现前后关系,本句的and was able to..可以写成 then was able to..吗？ 

【答】原句好好的，为何要改为错误的呢？先后顺序逻辑就可以给出，并列谓语动词，先说的动词发生在先，后说的动词在后，加上 then 属于多此一举。更为错误的是，这是用副词 then 替换连词and ，缺少了连词 and，就是错句！