请学长学姐吧我的问题复制下来,在每个问题和我的备注后面答题并解释,希望能多纠正我的一些盲点,告诉一些相关的语法知识,帮助

请学长学姐吧我的问题复制下来,在每个问题和我的备注后面答题并解释,希望能多纠正我的一些盲点,告诉一些相关的语法知识,帮助小弟早日得道,
—How did you get in touch with the travel agent,Robin?—Oh,that’s easy.I surfed the Internet and then called one ________ the telephonenumber is provided.A.which B.in which C.of which D.whose为什么这里不能选D,one是travel agent的代词 后面加whose,为什么不行?
The people,________ had been damaged by the flood,were given help by the Red Cross.A.all whose homes B.all of whose homes C.all their homes D.all of their homes 为什么选D就错,BD意思有什么不同吗?
Is this research center ________ you visited the modern equipment last year?A.where B.that C.the one that D.the one where为什么要选D,where就不行吗?research center算什么成分?
He had a lot of friends,only a few of ______ invited to his wedding.A.whom B.Them C.which D.Who这里答案上是B,可是only又不是连接词 为什么要选them?
On Sundays there were a lot of children playing in the park,_______ parents seated together joking.A.their B.Whose C.Which D.That这里答案上选的是A,为什么不能选B,不可以吧seated认为是过去式动词,together是副词吗?如果 选A 父母怎么会（被）坐在一起开玩笑?好像更不恰当啊,还有什么是独立主格结构?什么是插入语,两者什么区别?
If the man is only interested in your looks,_____ just shows how shallow he is.A.as B.which
C.what D.That这里答案上是D,好像说的是that指代前面整个句子,可是翻译起来很怪,（如果这个男人只注重你的外表）就让他知道他有多肤浅,我怎么觉得just前面要加you,因为是你让他知道他有多肤浅,不是这件事让他知道他有多肤浅吧,
Does Liu Hui serve in the army?—No,but he ________ in the army for three years.A.served B.has served C.is serving D.would serve 这里答案上选项是A,其实我看到no 也像选A,但是我看到for three years,这个是表持续的时间状语啊,所以我就选了B,完成时,有什么不对吗,如果说注重no,纳那个持续时间状语怎么解释?
You must have met him the other day.—Oh,no,I ________.A.hadn’t B.mustn’t C.haven’t D.didn’t
前面用完成时问 后面为什么不能用完成时回答,你一定在前几天见过他吧?我还没有,这样也可以吧为什么一定要选D
When I called you this morning,nobody answered the phone.Where ________?A.did you go B.have you gone C.were you D.had you been 这里我选对了,选C,但是我是靠语感,后来觉得did you go也很通顺啊,你那时去了哪里,为什么一定要选C呢?
Does Liu Hui serve in the army?—No,but he ________ in the army for three years.A.served B.has served C.is serving D.would serve 这里答案上选项是A,其实我看到no 也像选A,但是我看到for three years,这个是表持续的时间状语啊,所以我就选了B,完成时,有什么不对吗,如果说注重no,纳那个持续时间状语怎么解释?
选A啊,用一般过去式,表示动作已经结束了,而完成时表示动作持续到现在

1.d错的理由是因为有the.Whose+名词=of which the+名词= the+名词 of which,定语从句里经常遇见
2.定语从句里要用连接代词,连接副词等,而不是人称代词
3你把前句改成陈述句就是This research center is显然没先行词.
4同第二题
5后面是一个独立主格结构,如改成；Whose parents sat/were seated together joking就可以啊.seated是过去分词型的形容词.
6这是条件句和主句的关系,请记住英语中条件句和主句要齐全.
7他曾在部队服役三年,指过去,现在已不在部队了
8前面是情态动词表猜测,但回答用陈述句
9指过去的状态,而不是动作,人在哪儿?
相信你能理解和赞同,欢迎再问!祝你进步!