问题 选择题

下图表示高等动物的个体发育过程,下列说法正确的是

[ ]

A.图中①过程表示胚胎发育,②过程表示胚后发育

B.受精卵到囊胚形成的过程中,每个细胞的体积不断增大

C.爬行类、鸟类和哺乳类动物在胚胎发育过程中出现羊膜

D.囊胚期开始出现三胚层的分化

答案

答案:C

多项选择题
阅读理解

Museums have changed.They are no longer places that one “should”go but to enjoy.

At a science museum in Canada,you can feel your hair stand on end as harmless electricity passes through your body.At the Children’s Museum in New York,you can play an African drum.There are no “Do Not Touch”sign in some other museums in the USA.

More and more museum directors have realized that people learn beat when they can become part of what they are seeing.In many science museums,the visitors are encouraged to touch,listen,operate and experiment so as to discover scientific rules for themselves.

The purpose is not only to provide fun,but also help people feel at home in the world of science.If people don’t understand science,they will be afraid of it;and if they are afraid of science,they will not make the best use of it.

One cause of all these changes is the increase in wealth and spare time.Another cause is the growing number of young people in the population.Many of them are college students or college graduates.They see things in a new and different way.They want art that they can take part in.The same is true of science and history.

The old museums have been changing and the government is encouraging the building of new,modern museums.In the States and Canada,there are more than 6 000 museums,almost twice as many as there were 25 years ago.

53.The directors of the museums have realized______.

A.people learn beat when they look at something.

B.visitors prefer to learn from museums

C.people are interested if they take part

D.the importance of scientific rules

54.Why has the growing population of young people caused the changes in museums?

A.Because they are stronger.

B.Because they have less spare time.

C.Because they are better educated.

D.Because there are more young people.

55.Which of the following is not shown in Paragraph Two?

A.People are encouraged to take part in what they are seeing.

B.People are enjoying themselves fully in modern museums.

C.People will understand better by trying to discover the scientific rules themselves.

D.People should go to a museum to learn something.