人的性格特征按机能划分一般可分为情绪特征、（）特征和（）特征。

通过下列哪种途径可以实现民族的消亡（）.

A.民族同化

B.民族分化

C.民族融合

D.民族组合

若a^m﹣2bⁿ⁺⁷与﹣3a⁴b⁴是同类项，则m﹣n=(      )

关于以下毒性弥漫性甲状腺肿合并周期性麻痹的描写正确的是

A．大量钾离子从尿中排出

B．大量钾离子从肠道排出

C．血中钾离子向细胞内转移

D．大量出汗，钾离子从皮肤丧失

E．甲亢高代谢，而钾的摄入不足

阅读理解。

     Solar energy for your home is coming. It can help you as a single home owner. It can help the whole

country as well. Whether or not solar energy can save your money depends on many things. Where you

live is one factor and the type of home you have is another. Things like insulation (绝缘材料), present

energy costs, and the type of system you buy are added factors.

     Using solar energy can help save our precious fuel. As you know, our supplies of oil and gas are very

limited. There is just not enough on hand to meet all our future energy needs. Sooner or later Mother Nature

will say that's all. The only way we can delay hearing those words is by starting to save energy now and

by using other sources, like the sun.

     We won't have to worry about the sun's running out of energy for another several billion years or so.

Besides, the sun doesn't offer as many problems as other energy sources. For example, fossil fuel (矿物

燃料) adds to already high pollution levels. With solar energy, we will still need sources of energy, but we

won't need as much. That means we can cut down on our pollution problems. With all these good points,

why don't we use more solar power? There are many reasons for this. The biggest reason is money. Until

now, it was just not practical for a home owner to put in a solar unit. There were cheaper sources of energy.

     All that is changing now. Solar costs are starting to equal the costs of oil and electricity. Experts say

that gas, oil and electricity prices will continue to rise. The demand for electricity is increasing rapidly. But

new power plants will use more gas, oil or coal. Already in some places the supply of electricity is being

rationed (限量供应). Solar energy is now in its infancy (初期). It could soon grow to become a major part

of our nation's energy supply.

1. What's this passage mainly about? [ ]

A. Something about solar energy and pollution.

B. Solar energy.

C. Energy and pollution.

D. Energy and money.

2. Solar energy can help us _____. [ ]

A. escape punishment from nature

B. become home owners

C. get rid of present energy

D. save our precious fuel

3. The sun is an endless source of energy, and it will not run out of energy for _____. [ ]

A. several million years

B. several hundred years

C. several billion years

D. several thousand years

4. Which of the following statements is TRUE? [ ]

A. Energy from coal would not pollute our living environment.

B. Energy from natural gas would not pollute our living environment.

C. Energy from the sun would not pollute our living environment.

D. Energy from oil would not pollute our living environment.

5. Solar energy is now in its infancy, _____. [ ]

A. but in the future it will become an important part of our nation's energy supply

B. so we will build more power plants

C. and the supply of electricity will be rationed throughout the country

D. so we don't need it

下列化学方程式书写正确的是（　　）

A．S+O₂=SO₂

B．S+O₂=SO₂↑

C．2S+O₂=2SO₂

D．S+O₂