It is not easy to describe a policeman’s job. After all a policeman has a number of jobs

问题补充：

It is not easy to describe a policeman’s job. After all, a policeman has a number of jobs in .

A. it

B. one

C. his

D. that

答案：

A. it

(答案→)B. one

C. his

D. that

解析：考查代词：用it的话是直接指代policeman，而用one是用来强调policeman作为一份工作，相当于one job。句意：很难描述警察的工作，毕竟一个警察一份工作里面有很多事。选B。