题目

如图所示，四根相同的轻质弹簧连着相同的物体，在外力作用下做不同的运动： ⑴在光滑水平面上做加速度大小为g的匀加速直线运动 ⑵在光滑斜面上做向上的匀速直线运动 ⑶做竖直向下的匀速直线运动⑷做竖直向上的加速度大小为g的匀加速直线运动．设四根弹簧伸长量分别为△l1、△l2、△l3、△l4 ， 不计空气阻力，g为重力加速度，则下列关系式错误的是（ ） A . △l1＞△l2 B . △l3＜△l4 C . △l1＜△l4 D . △l2=△l3补全对话。根据对话内容，从方框中选出适当的选项补全对话。A: Look, a CD is on the floor.1.B: Let me have a look. Oh, it’s not a CD. It’s a movie DVD.A.2.B: It might be Peter’s. I saw a DVD in his hand just now.A:3.B: Action movies.A: But it’s a cartoon DVD.B: Oh, it could be Bill’s. He watched cartoons a lot.A: No.4. I saw Dave looking for something earlier today.B:Well, can the DVD be his? Oh, look!5.A:Whose?B:Dave’s.A. Whose DVD is it? B. It has a name on it.C.What kind of CD is it? D.I think it might be Dave’s.E.What kind of movies is Peter interested in?