1) Have you met Mr Liu?
你见过刘先生吗?
2) Do you know Mr Liu?
你认识刘先生吗?
4) Have you ever seen an owl?
你见过猫头鹰吗?
5) Have you ever seen the rainbow,
你见过彩虹吗?
6) Did you ever see a comet?
你看见过彗星吗?
参考词条