【题目】Television enables us to see things happen almost at the exact moment ________.
A.which they are happening
B.when they are happening
C.which is happening
D.when they have happened
在线课程【答案】B
【解析】
考查定语从句。句意：电视使我们几乎在事情发生的同一时刻看到它们发生。此处moment是先行词，在后面的定语从句中作时间状语，用when引导定语从句，再根据at the exact moment可知动作正在进行，所以用现在进行时态，故选B。