We all feel it is Jack as well as his wife that for their son’s bad performance at school

问题补充：

We all feel it is Jack as well as his wife that for their son’s bad performance at school.

A. are to blame

B. is to be blamed

C. are to be blamed

D. is to blame

答案：

A. are to blame

B. is to be blamed

C. are to be blamed

(答案→)D. is to blame

解析：考查blame的用法，和主谓一致，as well as后面的谓语动词由as well as前面的主语决定，即Jack，因此选择BD。Blame用法是sb be to blame，

句意为，我们都感觉是杰克和他的妻子应当为他们的儿子学校的糟糕表现负责。