11.17 將來完成時
?
 1) 構(gòu)成will / be going to do sth.
 2) 概念 
  a. 狀態(tài)完成:表示某事繼續(xù)到將來某一時為止一直有的狀態(tài)。
  b. 動作完成:表示將來某一時或另一個將來的動作之前,已經(jīng)完成的動作或一獲得的經(jīng)驗(yàn)。
   They will have been married for 20 years by then.
   You will have reached Shanghai by this time tomorrow.