在我市的北江河里有多种多样的生物,其中属于生产者的是[ ] A.鲫鱼 B.浮游动

题型:选择题

问题:

在我市的北江河里有多种多样的生物,其中属于生产者的是[ ]

A.鲫鱼

B.浮游动物

C.水藻

D.淤泥

考点:生态系统的概念和组成
题型:选择题
下列物理量为矢量的是(  )

A.平均速度

B.加速度

C.路程

D.时间

题型:选择题

220kV线路故障切除时间一般选择()。

A.0.12s

B.0.10s

C.近故障侧0.10s,远故障侧0.12s

D.0.15s

题型:选择题

下图所示的实验中,观察不到明显现象的是(  )

A.

B.

C.

D.

题型:选择题

Nuclear power’s danger to health, safety, and even life itself can be summed up in one word: radiation.

Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can’t be seen or heard, or touched or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can’t detect them, sense them, without a radio receiver. Similarly, we can’t sense radioactivity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things.

At very high levels, radiation can kill an animal or human being immediately by killing masses of cells in vital organs. But even the lowest levels can do serious damage. There is no levels of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be serious. This is the case when only a few cells are hit, and if they are killed immediately. Your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They can grow into cancer. Sometimes this does not show up for many years.

This is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can be irradiated(辐射)and feel fine, then die for cancer five, ten, or twenty years later as a result. Or a child can be born weak as a result of radiation absorbed by its grandparents.     

Radiation can hurt us. We must know the truth.         

小题1:Which of the following statements is true?                   

A.Nuclear radiation is just like common radio waves.

B.Nuclear radiation can cause cancer to human beings.

C.Nuclear radiation can be detected by human senses.

D.Nuclear radiation can be safe to human beings if its level is low.小题2:How can nuclear radiation kill an animal?                    

A.By damaging its heart.

B.By killing a few cells.

C.By hitting any place in its body.

D.By killing many cells in important organs.小题3: If a human being is hit by nuclear radiation, he may _______.

A.die of cancer after many years

B.die immediately

C.have a child who may be born weak

D.all of the above

题型:选择题

心肺热毒所致的火疳,常用的方剂是:()

A.泻肺饮

B.泻白散

C.驱风散热饮子

D.还阴救苦汤

E.栀子胜奇散

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