幾種容易混淆的時態比較（二）之二

　　bsp; be back

　　 fall asleep/go to sleep be asleep

　　1. 他已出去了。他出去了好幾個小時了。

　　 2.他已睡著了。睡著了好一會兒了。

　　 ２、make sure/be sure表示采取措施以保證之意時，從句中的時態用一般時或完成時。

　　 1.Make sure that you ______(turn) off the light when you leave.

　　 離開時務必關燈。

　　 2.Make sure that you ________(finish) the work before six.

　　 務必在六點前結束工作。

　　 3.The hunter held his hand tightly to be sure that he didn't bow,either.

　　 那位獵人緊握他兒子的手，以使他也不低頭鞠躬。

　　 ３、在時間狀語或條件狀語從句中，用一般現在時或現在完成時表示一般將來時，一般過去時或過去完成時表示過去將來時。

　　 1.Tell him about that when he _______(come).

　　 2.His daughter won't go to bed until she _______(finish) her homework.

　　 3.We would get into trouble as soon as the gas _______( run ) out.