帮我啊,谢谢
热心网友
下列情形时,只用as, 而不用when或while。 1)用于表示同一个人的两种动作交替进行,指一边----一边。 如: The girl sings as she goes to school。 He looked behind occasionally as he went forward in the forest。 2)表示两个同步发生的动作或行为,意思是随着-----的发展。如: As time went on / by, she became more and more beautiful 。 As children get older, they become more and more interested in everything。 3)表示两个短暂行为或事情几乎同时发生。如:I watched her as she read the book。 I thought of it just as you opened your mouth。 Just as the flying worm hit her face, she gave a loud cry。 4)接在名词后面表示某一个年龄段时。如: As a young man, he was active in sports。 ②when作"当……的时候"解,可以指较短的(一点)时间,也可指一段时间。如:When I was at college, I could speak several foreign languages。 When the clock struck twelve, I had slept for 2hours。 ③ while常表示一段较长的时间或一个过程,强调主句谓语动词与从句谓语动词同时发生。如:Work while you work。 Play while you play。 。