问题 选择题
如图所示,在x轴上方存在着垂直于纸面向里、磁感应强度为B的匀强磁场,一个不计重力的带电粒子从坐标原点O处以速度v进入磁场,粒子进人磁场时的速度方向垂直于磁场且与x轴正方向成120°角,若粒子穿过y轴正半轴后在磁场中到x轴的最大距离为a,则该粒子的比荷和所带电荷的正负是(  )

A.,正电荷

B.,正电荷

C.,负电荷

D.,负电荷

答案

答案:C

阅读理解

These days,more and more young people wish to be more beautiful,So they turn to plastic surgery(整形手术)for help.They spend thousands of yuan on these painful surgeries to fix(修整)their nose,to change their eyelids(眼皮)or to take off weight from their stomachs.

In fact,most people are not pleased with the way they look.Even the most beautiful actresses

often wish they could change something about their looks.Should we live our whole lives believing we are ugly? Why can’t we raise our head high and believe that we are as beautiful as others? A smile is beautiful on any face,whether fat,oily or hairy.And a kind heart is much more beautiful than a pretty look.

So,let’s feel grateful(感激的)that we all have beautiful and healthy bodies that do not need surgeries! Today,I call on you to make an easy change:hold your head high! smile and be kind to others.If you do these,you will be full of confidence(自信),beauty, and warmth everywhere you go.

小题1:How can we feel great about ourselves according to the writer?

A.Hold your head up.

B.Smile.

C.Be kind.

D.A, B and C小题2:The writer suggests we should believe we are as     as others

A.confident

B.good

C.beautiful

D.clever小题3:Which is Not true according to the passage?

A.Actresses never worry about their looks.

B.It costs a lot of money to have plastic surgeries.

C.We only need to make a small change to feel beautiful enough.

D.A good look is less important than a kind heart.

单项选择题