5. “Was his father very strict with him
题型：选择题
问题：
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
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