8. when 可用作并列连词,表示“这时”;while 也可以用作并列连词,表示“而”、“却”;但 as 则没有类似用法。如: We were about to start when it began to rain. 我们正要出发,这时天开始下雨了。 He likes coffee, while she likes tea. 他喜欢咖啡,而她却喜欢茶...
时间状语从句是要重点掌握的一类状语从句,其中,较难的有以下几个连接词:1.when;2.while;3.since;4.before;5. till,until, not …until。 when可作并列连词,常用于引导一个突然出现的动作,意为“那时/这时……”,此时句子的形式如下:1.Somebody was doing something wh...
31. Ben studied the menu for ___ while and then ordered his meal. A) a B) an C) the D) / 32. - Simon could look after ___ when he was five. - Really? How independent he was...
更多内容请点击：高考英语词汇详解:as,when,while的用法区别详解