I'm thankful to the soldier,without _____ rescue,my son would have been drowned.A.whose B.which C.whom D.hisThe students were busy going over their lessons,only ____once in a while to have a rest.A.to stop B.stopping C.stoppe

I'm thankful to the soldier,without _____ rescue,my son would have been drowned.A.whose B.which C.whom D.hisThe students were busy going over their lessons,only ____once in a while to have a rest.A.to stop B.stopping C.stoppe
I'm thankful to the soldier,without _____ rescue,my son would have been drowned.
A.whose    B.which    C.whom       D.his


The students were busy going over their lessons,only ____once in a while to have a rest.
A.to stop      B.stopping     C.stopped      D.having stopped
第一题选D不可以么,这是什么句式啊?
第二个为什么一定用现在分词呢,这是什么用法,不定时不行么?
本人学术不精,请各位老师说细一下哈,谢绝只写个答案,请讲清楚我的问题（可能很二哈）,多谢您的回答.

I'm thankful to the soldier,without _____ rescue,my son would have been drowned.A.whose B.which C.whom D.hisThe students were busy going over their lessons,only ____once in a while to have a rest.A.to stop B.stopping C.stoppe
I'm thankful to the soldier,without _____ rescue, my son would have been drowned.
A.whose B.which C.whom D.his
第一题不能选his是因为这里是一个定语从句.选D的话句子没有并列连词连接,题干的两个部分不能这样直接并列起来.而选whose的话后半截句子就变为定语从句,whose也是连接词,连接这个从句和前面的主句.
如果要想D正确的话,就要把这题干变为并列句或者两个单独的句子,也就是要么把soldier后面的逗号改为句号（这样的话题干就变为了两个独立的句子）,要么就在without前面添上and(这样的话题干就变为了并列句,and是并列连词,用于连接并列的句子,but和or也是属于并列连词)
The students were busy going over their lessons,only ____once in a while to have a rest.
A.to stop B.stopping C.stopped D.having stopped
这道题是现在分词做伴随状语用.不定式虽然也可以做状语用,但一般而言 to do做状语是表示目的,或者是表示出乎意料的结果.我举个例子：
She wanted to go to Taiwan to see the TV star.第二个to do 就是目的状语.
She took a taxi to the airport, only to find that the star had gone. 她打的到机场,却发现明星早走了.（这个就是典型的to do做状语表达出乎预料的结果）

楼主,这样子够详细了吧.纯手打,望采纳.