问题 多选题

铝核1327Al被α粒子击中后产生的反应生成物是磷1530P,同时放出一种粒子,关于这种粒子的下列说法中正确的是(  )

A.这种粒子在电场中可以被加速或发生偏转

B.这种粒子在磁场中一定不受磁场力作用

C.这种粒子在真空中的速度等于3×108m/s

D.在碳14核内有8个这种粒子

答案

根据质量数和电荷数守恒可知放出的粒子质量数为1,电荷数为0,故该粒子为中子,中子不带电不会在电场中加速或偏转,也不会受到磁场力作用,故A错误,B正确;

该粒子的速度小于光速,故C错误;

碳14核的电荷数为6,中子数为14-6=8个,故D正确.

故选BD.

选择题
阅读理解

Australia is the smallest continent in the world. It is a little smaller than China. It is on the Southern Hemisphere(半球)of the earth. Australia is big, but its population is small. The population of Australia is nearly as large as that of Shanghai.

Enough laws have been made to fight against pollution. The cities in Australia have little air or water pollution. The sky is blue and the water is clean. You can clearly see fish in the rivers. Plants grow very well.

Last month we visited Perth, the biggest city in Western Australia, and went to a wild flower exhibition. There we saw large numbers of wild flowers on show, most of which we had never seen before. We had a wonderful time. Perth is famous for its beautiful wild flowers. Every year in spring Perth has wild flower exhibitions. After visiting Perth, we spent a day in the countryside. We sat down and had a rest near a path at the foot of a hill. It was quiet and we enjoyed ourselves very much. When we heard bells ringing at the top of the hill, we looked up, but what we saw made us pick up all our things and run back to our car as quickly as we could. There were about three hundred sheep coming towards us along the path.

Australia is famous for its sheep and kangaroos(袋鼠). After a short drive from any town, you will find yourself among the white sheep. Sheep, sheep, everywhere you can see sheep.

小题1:Which country is the writer most possibly from?

A.Japan

B.Canada

C.China

D.America小题2:Which of the following statements is not true according to the passage?

A.Australia has enough laws to fight against pollution.

B.Perth is the biggest city in Australia.

C.The wild flowers in Perth must be different from what the author sees in his/her country.

D.The author enjoyed his/her visit in the countryside.小题3:The underlined word “exhibition” in the third paragraph probably means_______.

A.a public show for people to visit

B.a market where you can buy all kinds of flowers

C.a place where all kinds of flowers are grown

D.a field where there are flowers and animals小题4:From the passage we know Perth is famous for ____

A.its population

B.its size

C.its kangaroos

D.its wild flowers