________ it was very late, ________ he was still doing some experiments in the lab．
A.Although; but
B.Although; yet
C.Even though; but
D.Though; but
网友回答
B解析although/though可以和still、yet连用，但不可以和but连用，所以选择B．本句是一个让步状语从句，而且带有副词．句子的意思是“尽管已经很晚了，他依旧在实验室做实验”．