2019学年度北师大版选修七Unit 20 Period 5Grammar & Writing课件(24张)
2019学年度北师大版选修七Unit 20 Period 5Grammar & Writing课件(24张)第4页

2.用法 (1)表示在将来某一时间之前已完成的动作,并可能对将来产生影响。 We shall have learned 12 units by the end of this term. 到这个学期末,我们将学完12个单元。 By the time you get home,I will have cleaned the house from top to bottom. 你到家之前我将已经把房子彻底打扫一遍了。