--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

用于治疗神经官能症的抗焦虑药为

A．地西洋

B．氯氮卓

C．甲丙氨酯

D．甲喹酮

E．水合氯醛