tim has been in australia for six mouth.his brother hasn't seen him _january.1for2since3from4by为什么
问题描述:
tim has been in australia for six mouth.his brother hasn't seen him _january.
1for
2since
3from
4by
为什么
答
前面是hasn't seen,是完成时,与完成时连用的只有since
所以选2
Do you understand?