Mum my trousers are too old. I want to buy a new .A. trousersB. oneC. itD. pair

问题补充：

Mum, my trousers are too old. I want to buy a new .

A. trousers

B. one

C. it

D. pair

答案：

A. trousers

B. one

C. it

(答案→)D. pair

解析：句意：妈妈，我的裤子太旧了，我想买条新的。a pair of trousers一条裤子，故选D。