一个质点做匀速圆周运动时，它在任意相等的时间内（ ） A．通过的位移相等 B．通

“真理是时间的女儿，不是权威的女儿。”这句名言是指[ ]

A、真理与权威是相互排斥的

B、真理要靠历史和实践来检验

C、真理与权威是相互依存的

D、只有服从真理，才能具有权威

当代青少年所肩负的历史责任是[ ]

A．努力学习，提高综合素质

B．树立远大理想，实现人生价值

C．争取国家独立.民族解放              

D．实现中 * * 的伟大复兴

为避免感染性物质的注入，下列哪个选项是错误的：（）

A、应尽可能用玻璃制品代替塑料制品

B、避免锐器损伤

C、减少针刺损伤

D、一次性物品应丢弃在防、耐穿透的带盖容器中

Can you remember the day when you spoke your first word? If you can, you are unusual. Try to imagine what first few months of your life were like. I am sure you just spent most of your time eating, sleeping and crying. As you grow older, you were awake more of the time. It took your parents more time to play with you and talk to you. You watched and listened curiously. You began to know that people made certain sounds to go with certain things.

Then you began to try making the sounds you heard. And step by step you were able to make the right sound for one thing.On that day you came to understand the secret of language. The secret is that a certain sound means a certain thing. One sound might be as good as another. But it is no good as a word unless everybody agrees on its meaning. Only when a group of people use the same set of sounds of things, can they understand each other. Then, and only then do these people have a LANGUAGE.

After you found the secret of language, you learned words. Some of the words meant things, such as BOOKS, CHAIRS and SHOES. Some words meant doing things, such as GO and SWIM. And other words describe things, such as GOOD and DIRTY. Soon you learned to put words together to express one’s idea, such as “I want to go out and play with my friends.” This is language. By means of language people can communicate. So we say languages are means of communication.

小题1:When you were a little baby, you_________.

A．made sounds to let people know that you wanted to eat

B．spent most of your time playing with your parents

C．could not hear any sound around you

D．spent most of your time eating, playing and crying小题2:The secret of language is that___________.

A．one sound might be as good as another

B．people can understand each other

C．a certain sound is for a certain thing

D．there is a special sound for each person小题3:You could learn words__________.

A．before you knew what the language was

B．after you knew what the language was

C．if you knew the secret of the language

D．when you were a baby小题4:The aim in using language is___________.

A．to get everying one wants from others

B．to say what one wants to know

C．to share ideas, opinions, news, etc with one another

D．to make oneself understood by others

目前，我国青少年近视率的整体水平仅次于日本，为36.17%，居世界第二位．青少年近视不仅影响现在的学习，而且对将来的工作和学习都会造成很大影响．下列措施中不能预防近视的是（　　）

A．看书写字一小时左右就应该休息远眺

B．眼睛与书本的距离保持在30厘米左右

C．看书写字时光线越强越好

D．每天坚持认真做眼保健操