Adverbial Clause2nd状语从句经典(5)

1.当Tom正在看电视的时候,他的妻子正在做饭。 While Tom was watching TV, his wife was cooking. 2.在你离开教室之前,请关上灯。 Turn off the light before you leave the classroom. 3.在他完成作业后，他离开了那。(after/before) After he finished his work, he left there. After finishing his work, he left there. He finished his work before he left there.