(格式最好是：句意+原因/语法点）

(格式最好是：句意+原因/语法点）
1、If you compare food costs today _____ of a year ago,you will find the difference.
A.to that B.to them C.with that D.with those
帮分析一下A哪错!
2、Only _____ as an interpreter______ how important it is to grasp English
不打选项了,问：when I worked;did I realize 为何对?
3、It was the training ____ he had as a young man ____ made him such a engineer.
A.what;what B.which;that C.that;which D.that;what
4、it was 和 was it 有何区别?
以上题做题的技巧是神马?Thanks!

1. costs 为复数 ,但是that 只能代表单数,故要用those 了.
2. only 位于句首需要倒装的这个单选题应该是用排除法做出来的,前面woked 已经用了过去式,所以后面要说did 而不是 had ,is 之类的.另外后面的realize 就必须用一般现在时了,因为前面已经用过一次did 了.
3、这个显然是一个it ,that 强调句型 ,这种句子一般最后一个空都是that ,所以直接就有答案了,前面一空用which ,不填也可以.it that 用法如下
1. I am right. 我是对的.
It is I that/who am right. 正确的是我.
2. We met a foreigner at the school gate. 我们在校门口遇见一位老外.
It was a foreigner that/whom we met at the school gate.
我们在校门口遇见的是一位老外.
3. Tom lost his wallet in the supermarket. 汤姆在超市里丢了钱包.
It was in the supermarket that Tom lost his wallet. 汤姆是在超市里丢的钱包.
4. She didn’t go to work because her mother was ill. 因为妈妈病了,她没去上班.
It was because her mother was ill that she didn’t go to work.
她没去上班是因为妈妈病了.
5. The Second World War broke out in 1939. 二战爆发于1939年.
背诵下面的对你以后很有用处.
比较 a. It was at midnight that I got back home yesterday.
It was midnight when I got back home yesterday.
b. It was two years ago that I began to learn French.
It is/has been two years since I began to learn French.
c. It was two years later that he came back from abroad.
It was two years before he came back from abroad.
d. It is in two years that he will graduate from college.
It will be two years before he graduates from college.
e. It was in a mountain village that we met for the first time.
It was a mountain village where we wet for the first time.
4.这个实在不好说,一个用到陈述句,一个用到疑问句,不知道你想要问什么,你这个问题就好像是在说是的和是吗什么区别.
It was in 1939 that the Second World War broke out. 二战是在1939年爆发的.
6. He didn’t go to bed until ten o’clock.他
It was not until ten o’clock that he went to bed.
再问： 呃，我主要想问这俩词后面+that有何区别，很感谢你能复制例句（但最后两句有问题吧！中文。。）
再答： 不好意思，我给你翻译一下，他直到十点才睡觉，你把这几个句子背会，以后出道这些题你就不会错了，其实英语很多时候是你先要背会然后再去理解，就想吃东西，你要先吃下去，然后才可以去评价回味，不能什么也不吃就拿着筷子对着这东西说好吃不好吃，实践出真知，语言学习是需要先囫囵吞枣的。
再问： 恩，说的极是，您很有经验，再问一下：which 和 that 在做选择题时该如何辨别或这俩词有何本质上的差异；介词可以位于句尾么（如：paid for..)？很感谢！！！
再答： 这涉及到定语从句了，　我记得初中时候是还没有学这个的　，你可以自己去看看，介词是可以放于句尾的，而且还有很多用法，举一个简单的例子，where are you from?这里就是介词位于句尾。