Question

He took medicine 3 times a day,________ didn't work.

A．it

B．but

C．which

D．but which

Answer 1

C

试题分析：句意：他一天吃三次药，这不奏效。这里需要非限制性定语从句，用which引导，指代前面的句子，在定语从句中which做主语，如果用but连接并列句，应该是but it…，所以选C。