问题
选择题
It has been 4 years _____ the earthquake happened in Wenchuan
A．when
B．since
C．after
D．while
答案
答案：B
本题为固定搭配：It have/has been +一段时间+since +一般过去时。故选B
搜题请搜索小程序“爱下问搜题”
It has been 4 years _____ the earthquake happened in Wenchuan
A．when
B．since
C．after
D．while
答案：B
本题为固定搭配：It have/has been +一段时间+since +一般过去时。故选B