问题 选择题

将一只小球水平抛出,小球在空中依次飞过1号、2号、3号三个完全相同的窗户,图中曲线为小球在空中运行的轨迹.若不计空气阻力的影响,以下说法正确的是(  )

A.小球通过3号窗户所用的时间最长

B.小球通过1号窗户所用的时间最长

C.小球通过3个窗户的时间是相同的

D.3个窗户所截得的小球运动轨迹相同

答案

A、平抛运动在竖直方向上做自由落体运动,速度越来越大,知通过窗户所需的时间越来越短,小球通过3号窗户所用的时间最短.故A错误.

B、由A分析知,B正确.

C、由A分析知.C错误.

D、竖直高度相同但水平位移不同,故D错误.

故选:B.

改错题

 短文改错(共10小题;每小题1分,满分10分)

此题要求改正所给短文中的错误。对标有题号的每一行作出判断:如无错误,在该行右边横线上画一个(√);如有错误(每行只有一个错误),则按下列情况改正:

该行多一个词:把多余的词用斜线(﹨)划掉,在该行右边横线上写出该词,并也用斜线划掉。

该行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线写出该加的词。

该行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。

Bill worked in big office,and he usually went to the barber’s                          61.________

during working hours to have his hair cut.This against the                                   62.________

rules:office workers had to have his hair cut in their own time.                              63.________

While Bill was at the barber’s on one day,the manager of the                                 64.________

office entered in to have his own hair cut.Bill saw him and                                    65.________

managed to hide his face.But the manager sat beside him,and                                 66.________

soon recognized him.

“Hello,Bill,” said the manager,“I know you are having your haircut.”      67.________

“Yes,sir,I do,” said Bill.“You see,sir,it grows in office time.”                  68.________

“Not all of it,” said the manager at once.“Some grows in your own time.”             69.________

“Yes,sir,that’s quite true,” answered Bill polite,“but I’m not having it all         70.________

cut off.”