Both of my parents insisted a computer for me but I don’t think it is necessary.A. to bu

问题补充：

Both of my parents insisted a computer for me, but I don’t think it is necessary.

A. to buy

B. buying

C. on buying

D. in buying

答案：

A. to buy

B. buying

(答案→)C. on buying

D. in buying

解析：其实，动词 insist 后既不能接不定式也不能接动名词，因为insist 通常用作不及物动词；若语义上需接宾语，要借助介词 on或upon，即用于 insist on [upon] (doing) sth；但它有时的确也可用作及物动词，不过其宾语通常只能是 that 从句，而不能是普通的名词、代词或动名词。