how long have you(been)
2018-01-30 0评论
present perfect continous and simple
2018-01-30 0评论
present perfect continuoud
2018-01-30 0评论
present perfect
2018-01-30 0评论
past continous
2018-01-30 0评论
past simple
2018-01-30 0评论
present continuous and present simple
2018-01-29 0评论
present simple(I do)
2018-01-29 0评论
present continous
2018-01-29 0评论
祈使句
2017-12-17 0评论