据报道,某些建筑材料会产生放射性同位素氡,从而对人体产生伤害,该同位素原子的中子

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问题:

据报道,某些建筑材料会产生放射性同位素氡,从而对人体产生伤害,该同位素原子的中子数和质子数之差是 [ ]

A.136

B.50

C.86

D.222

考点:原子核的组成及组成粒子间的关系
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儿童单纯性肥胖症可能伴有的内分泌变化为

()

A.血清PTH水平升高

B.25-(OH)D及24、25-(OH)D水平降低

C.生长激素水平增高

D.尿17-羟类固醇水平降低

E.血胰岛素水平降低

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用于调整镜圈的面弧弯度,称()。

A、框缘钳

B、定位钳

C、托叶钳

D、分嘴钳

题型:不定项选择题

Healthy Diet“An apple a day keeps the doctor away.” Similarly, if we drink a little more water ever day, we may find that we need to go to the doctor a lot less often. A healthy diet is made up of water and a great many different kinds of foods. We know that healthy foods like fruits, vegetables and fish, are important as they provide us with energy and fibre, without giving us too much fat and sugar. But why is water important?

The human body needs water to survive. Water is important as it carries poisons and waste out of our bodies. However, doctors advise us to drink plenty of water, much more than the small amount we need to stay alive.

Some doctors believe that water is important for our health in all kinds of ways. They believe that a great many illnesses and health problems stars as a result of dehydration—a lack(缺少) of water in the body. Most people are dehydrated at least some of time, although they probably don’t know it. It is surprising to learn that if we feel thirsty, we are already in the first stages of dehydration. In fact, we are advised to drink water before we feel thirsty.

These doctors think that health problems such as headaches, high blood pressure and asthma could be helped if people drink more water. They also believe that drinking more water can help people who are overweight. Water contains no calories so it will not make us put on weight. If we drink water, we will probably drink less sugary soft drinks such as Coca-cola. Doctors also believe that drinking more water may stop people from overeating. They say that many people think that they are hungry when they are, in fact, thirsty. Doctors suggest, therefore, that we eat less food and drink more water.

There are still many health problems that cannot be solved by drinking water, so we should not stop going to seeing the doctor completely. However, if we make a decision to drink water every day, we may find that we need to go to the doctor a lot less often.

小题1:We need _____for a healthy diet.

A.fibre

B.food

C.water

D.Water and different foods小题2:From the text, we know water can carry_________.

A.energy and fibre in our bodies

B.fruit, vegetables and fish in our bodies

C.sugar and fat out of our bodies

D.poisons and waste out of our bodies小题3:Some doctors think that________.

A.people eat too much sugar

B.water is not important for our health

C.we should go to the doctor less often

D.some health problems are caused by a lack of water小题4: Lack of water caused people to put on weight too much because_______.

A.they think they are hungry and eat too much

B.they think they are thirsty and eat less

C.water has no calories

D.it makes them hungry

题型:不定项选择题

业主大会会议分为( )。

A.书面征求意见和集体讨论

B.定期会议和书面征求意见

C.定期会议和临时会议

D.临时会议和集体讨论

题型:不定项选择题

双排脚手架内外排架为什么必须同时拉结?

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