问题补充:
More wild tigers have been seen in the forest around this area, there used to be very few.
A. when
B. where
C. what
D. which
答案:
A. when
(答案→)B. where
C. what
D. which
解析:定语从句缺少地点状语in the forest,所以其关系词必须是where或in which.
答案A在定语从句中做时间状语; C what不能引导定语从句; D的which只能直接代替先行词the forest,但是它不能在该定语从句中直接充当成分。