--I have given up smoking already, darling.

--You should have taken the doctor’s advice years ago.       .

A．Easier said than done.

B．Better late than never.

C．No pains, no gains

D．Well begun is half done.

C-烷基化就是利用烷基化剂把（）连在芳环上的反应。

A、硝基

B、烷基

C、磺基