1. —Mum, my trousers (are/is) too short. Can I buy a new pair?
—Sure. You need a new pair of (trousers/shorts).
2. —Look at my coat. (This/These) one is too small.
—Oh, yes. Let's go to the (clothes/book) shop.
3. —(Those/That) shorts are too short.
—OK. Let's buy a new (pair/chair).

1. are, trousers
2. This, clothes
3. Those, pair

1. 第一句中 trousers 为复数形式，所以 be 动词用 are。根据题意，买的是一条新裤子，所以选择 trousers。
2. 指代单数可数名词（coat）用 this 或 that，此处用 this one。去商店买衣服应选择 clothes shop。
3. 指代复数名词 shorts 用 those。短裤的单位一般用 pair。

John: Mum, my coat is small. 1.
Mum: OK. You need a new coat.
John: 2. How about the new trousers?
Mum: The trousers are nice.
John: 3.
Mum: Sorry, John. 4. Let's buy a coat and a pair of trousers.
John: OK, Mum.
|A. My trousers are too short.|B. Can I buy a toy car too?|
|C. You already have too many toy cars.|D. Can I buy this new coat?|

1. D
2. A
3. B
4. C

|John needs|pen|trousers|shirt|

|---|---|---|---|
||toy car|coat|
|John wants|pen|toy car|shorts|
||cap|book|

答案略