羊毛按纤维结构分有()四类毛。A.绒毛.两型毛.粗毛.死毛 B.同质毛.绒毛.粗毛.

题型:单项选择题

问题:

羊毛按纤维结构分有()四类毛。

A.绒毛.两型毛.粗毛.死毛

B.同质毛.绒毛.粗毛.死毛

C.绒毛.两型毛.粗毛

D.同质毛.粗毛.死毛

考点:纺织科学技术针织挡车初级工针织挡车初级工题库
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MCS-51单片机的复位电平均为低电平,其持续(保持)时间应在2个机器周期以上。

题型:单项选择题

We each have a memory(记忆力). That’s why we can still remember things after a long time. Some people have very good memories and they can easily learn many things by heart, but some people can only remember things when they say or do them again and again. Many of the great men of the world have got surprising memories.

A good memory is a great help in learning a language. Everybody learns his mother language when he is a small child. He hears the sounds, remembers them and then he learns to speak. Some children are living with their parents in foreign countries. They can learn two languages as easily as one because they hear, remember and speak two languages every day. In school it is not so easy to learn a foreign language because the pupils have so little time for it, and they are busy with other subjects, too.

But your memory will become better and better when you do more and more exercises.

小题1:、Some people can easily learn many things by heart because                .

A.they always sleep very well

B.they often eat good food

C.they read a lot of books

D.they have very good memories小题2:.、Everybody learns his mother language         .

A.at the age of six

B.when he is a small child

C.after he goes to school

D.when he can read and write小题3:.、Before a child can speak, he must              .

A.read and write

B.make sentences

C.hear and remember the sounds

D.think hard小题4:.、In school the pupils can’t learn a foreign language well because          .

A.they have no good memories

B.they have no recorders

C.they have too much time for it

D.they are busy with other subjects小题5:.、Your memory will become better and better          .

A.if you have plenty of good food

B.if you do more and more exercises

C.if you do morning exercises every day

D.if you get up early

题型:单项选择题

按带式输送机输送带宽度不同,机尾轨道的轨距有1362毫米和1100毫米两种规格。

题型:单项选择题

悬挂保护间隙应先将其与接地网可靠接地,再将保护间隙挂在导线上,并使其接触良好。拆除的程序与其相同。

题型:单项选择题

慢性肺心病呼吸衰竭血气分析常表现为()

A.PaO2<9.3kPa(70mmHg)

B.PaO2<8.0kPa(60mmHg)

C.PaO2<5.3kPa(40mmHg)

D.PaCO2>6.67kPa(50mmHg)

E.以上均不会出现

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