1. Everyone knows that _______ is dangerous to play with fire, but _______ is difficult is to prevent children from playing with fire.
A. it, it??? B. what, what
C. it, what??? D. what, it
【陷阱】很容易誤選B，認(rèn)為兩空均考查形式主語。
【分析】最佳答案是C，第一空填形式主語，真正的主語是其后的不定式 to play with fire。第二空填 what，what is difficult 是主語從句，注意 what is difficult 后的謂語動(dòng)詞 is。請(qǐng)做以下類似試題：
(1) I know ______ is important to know my own limitations, but _______ is difficult is to help others to know their own limitations.
A. it, it??? B. what, what
C. it, what??? D. what, it
(2) Yes, ______ is difficult to find a job nowadays, but _____ is more difficult is try to find such a job with a high salary but little things to do.
A. it, it??? B. what, what
C. it, what??? D. what, it

2. I dislike _______ when others laugh at me in public or think poorly of me behind.
A. that??? B. those
C. it??? D. them
【陷阱】幾個(gè)干擾項(xiàng)均有可能誤選。
【分析】最佳答案是C，因?yàn)樵谕ǔＧ闆r下，like 是及物動(dòng)詞，其后應(yīng)有賓語(句中 it 即為其賓語)。句中的 when 從句不是賓語從句，而是時(shí)間狀語從句，其中的 when 的意思是“當(dāng)……的時(shí)候”。其實(shí)，也有的詞典將 I don't like it when (if) … 作為一個(gè)句型來處理。能這樣用的動(dòng)詞不多，主要的有enjoy, like, dislike, love, hate, prefer, appreciate等表示喜好的動(dòng)詞。
She won't like it if you arrive late. 她不喜歡你遲到。
He hates it when people use his bike. 他討厭別人用他的自行車。
請(qǐng)做以下類似試題(答案均選 it)：
(1) I hate _______ if people say such things in public.
A. that????? B. those
C. it??? D. them
(2) I'd prefer _______ if I didn't have to get up early on Sundays.
A. that??? B. such
C. it??? D. which
(3) I would appreciate _______ very much if you could give me some suggestions.
A. this??? B. that
C. it??? D. you

3. I've no idea. I just pretended nobody was at home, so I didn't ask who _______ was.
A. he??? B. that
C. she??? D. it
【陷阱】容易誤選A或C。
【分析】最佳答案是D。it 用以指身份不明的人。若指身份明確的人，則不宜用it。比較：
(1) Mr Smith is at the door. _______ wants to see you.
(2) Someone is at the door. ________ must be Mr Smith.
A. He??????????? B. It
C. This??? D. That
第(1)題選A，因?yàn)閬碚呱矸菝鞔_；第(2)選B，因?yàn)閬碚呱矸莶幻鞔_。
?
4. "Excuse me, I want to have my watch fixed, but I can't find a repair shop." "I know ________ nearby. Come on, I'll show you."
A. one??? B. it???
C. some??? D. that
【陷阱】容易誤選B。
【分析】最佳答案是A。it 和 one 的區(qū)別可簡單地概括為：it = the + 名詞，one = a + 名詞。如：
I haven't got any pens, and I want to borrow one. 我沒有鋼筆，我想借一支。(one = a pen)
I have two pens, and I can lend one to you. 我有兩本支鋼筆，我可以借一支。(one = a pen)
I have a pen, and I can lend it to you. 我有一本鋼筆，我可以把它借給你。(it = the pen)
在上面一題中，one 相當(dāng)于 one 相當(dāng)于 a repair shop。請(qǐng)做下面一題（答案選A）：
There is only one English-Chinese dictionary in that book-shop. I wonder if you still want to buy _______.
A. it??? B. one
C. another??? D. any

5. Will you see to _______ that my children are taken good care of while I am away?
A. it??? B. me
C. yourself??? D. them
【陷阱】幾個(gè)干擾項(xiàng)均有可能誤選。
【分析】最佳答案是A。it 為形式賓語，真正的賓語是空格后that引導(dǎo)的賓語從句。see to 意為“負(fù)責(zé)”、“注意”，其中的 to 為介詞，不宜直接跟that引導(dǎo)的賓語從句，遇此情況可借助代詞 it。請(qǐng)做下面兩題，答案也是選 it：
(1) I'll see to _______ that all these letters will be sent to the post before twelve.
A. it??? B. me
C. which??? D. them
(2) Will you see to _______ that the luggage is brought back as soon as possible?
A. me??? B. yourself
C. it??? D. them
類似以上 see to 用法的短語還有 depend on, answer for 等。如下面兩題答案也選 it：
(1) You may depend on _______ that he will turn up in time.
A. it??? B. me
C. which??? D. them
(2) I can't answer for ________ that the boy is honest.
A. it??? B. me
C. which??? D. them