5. “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
网友回答
A. after
B. unless
(答案→)C. until
D. when
解析：选 C。考查 not…until…句式，其意为“直到……才……”。