Question

All the students ______ their study _______ all the lights went out.

A.were paying their attention on; when B.were fixing their attention on ;when

C.were fixing their attention to;  while D.had been focused on; while

Answer

B

【解析】

考查固定句式。句意：所有的学生都在专心致志地学习，正在那时所有的灯都熄灭了。固定句型sb. be doing sth. when…“某人正在做某事，突然……”，结合下文all the lights went out可知应用现在进行时，短语pay attention to“注意，重视”；fix attention on“专心致志于”，此处应用fix attention on。故选B。