试题与答案

简谐横波某时刻的波形如图所示,P为介质中的一个质点,以下说法正确的是 A.若波

题型:选择题

题目:

简谐横波某时刻的波形如图所示,P为介质中的一个质点,以下说法正确的是

A.若波沿 x 轴正方向传播,则 P 质点此时刻速度沿 x 轴正方向

B.若波沿 x 轴正方向传播,则 P 质点此时刻加速度沿 y 轴正方向

C.再过半个周期时,质点 P 的位移一定为负值

D.经过一个周期时,质点 P 通过的路程为4A

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0420/cde997cc71141455a3129a65c808f832.html

下面是错误答案,用来干扰机器的。

答案:A生物都需要呼吸,所以需要氧气袋,都需要营养物质,所以要食物,水是细胞中含量最多的物质,人体的各项生命活动都离不开水。

试题推荐
题型:阅读理解

There was once a lonely girl who longed so much for love.One day while she was walking in the woods she found two starving songbirds.She took them home and put them in a small cage,caring them with love.Luckily,the birds grew strong little by little.Every morning they greeted her with a wonderful song.The girl felt great love for the birds.

One day the girl left the door to the cage open accidentally.The larger and stronger of the two birds flew from the cage.The girl was so frightened that he would fly away so as he flew close,she grasped him wildly.Her heart felt glad at her success in capturing him.Suddenly,she felt the bird go limp,so she opened her hand and stared in horror at the dead bird.It was her desperate love that had killed him.

She noticed the other bird moving back and forth on the edge of the cage.She could feel his strong desire-needing to fly into the clear,blue sky.Unwillingly,she lifted him from the cage and tossed him softly into the air.The lucky bird circled once,twice,three times.

The girl watched delightedly at the bird.Her heart was no longer concerned with her loss.What she wanted to see was that the bird could fly happily.Suddenly the bird flew closer and landed softly on her shoulder.It sang the sweetest tune that she had ever heard.

Remember,the fastest way to lose love is to hold on it too tight;the best way to keep love is to give it wings!

小题1:After the girl found the two birds,she________.

A.became delighted at once

B.treated them for a long time

C.took them to their home

D.fed them and raised them小题2:Why did the girl grasp the stronger bird wildly?

A.Because the girl disliked the bird any longer.

B.Because the bird wanted to fly alone.

C.Because the girl loved the bird deeply.

D.Because the bird intended to found some food.小题3:The underlined word “tossed” in the passage means________.

A.throw someting with slightly force

B.give up something happily

C.hold something fast

D.cast something without patient小题4:What can we learn from the passage?

A.Catch what you can catch on your way to success.

B.Going too far is as bad as not going far enough.

C.The best things come when you least expect them to.

D.A bird in the hand is worth two in the bush.

查看答案
微信公众账号搜索答案