“Was his father very strict with him when he was at school?” “Yes. He had never praised hi

问题补充：

“Was his father very strict with him when he was at school?” “Yes. He had never praised him he became one of the top students in his grade.”

A. after

B. unless

C. until

D. when

答案：

A. after

B. unless

(答案→)C. until

D. when

解析：考查 not…until… 句式，其意为“直到……才……”。