--Jacks never worked hard at English ?-- so he cant answer the question in English

问题补充：

--Jacks never worked hard at English, ?

-- , so he can answer the question in English, I think.

A. is he; Yes, he is

B. is he; No, he isn

C. has he; Yes, he has

D. has he; No, he hasn

答案：

A. is he; Yes, he is

B. is he; No, he isn

C. has he; Yes, he has

(答案→)D. has he; No, he hasn

解析：Jack’s此处为Jack has的缩写，因句中有never，故附加问句应用has；答句说明的是否定情况，故应用N0，he hasn’t。