職稱英語考試句型語序：從句類型(1)

時間狀語從句

　　I) when，while和as

　　He entered the room when (while, as) the meeting was going on.

　　when 通常指一時的動作或狀態(tài)，可表示從句動作與主句動作同時發(fā)生，或先于主句動作;while常用來引導兩個同時進行的持續(xù)時間較長的動作;as常用來引導兩個動作緊接著發(fā)生，強調(diào)“同一時間”或“一前一后”。

　　When I meet the right chance, I will try my best.

　　While the teacher explained the text, the students listened attentively and took notes

　　He sang songs as he was taking a bath.

　　As spring warms the earth, all flowers begin to bloom.

　　注：when有時作并列連詞意為“正在這時”、“突然”，在句末，不能位于句首。從句的謂語動詞常用一般過去時，主句通常用過去進行時、過去完成時或be about to結構等。

　　She was about to leave when Mark arrived so she stayed a little longer.

　　He had been walking under the trees when an apple fell down. 考試用書

　?、? as soon as, hardly (scarcely, barely) … when… , no sooner …than… 等引導的時間狀語從句，意為“ 一… 就 …”

　　Jack had scarcely /hardly seen me when he left the room.

　　The spy had no sooner returned home than he was told to go to another country.

　　那個間諜一踏進國門就奉命要去他國。

　　注： 在no sooner … than, hardly … when …引導的時間狀語從句中，若把no sooner, hardly, scarcely, barely 放在句首，則要用倒裝結構。

　　No sooner had he heard the news than he fainted.

　　Scarcely had he entered the room when the telephone rang.