如图所示,MgCl2、Mg(OH)2、MgCO3、MgSO4都可以跟某些物质反应

题型:填空题

问题:

如图所示,MgCl2、Mg(OH)2、MgCO3、MgSO4都可以跟某些物质反应生成化合物x,则x的化学式为______,并写出反应①~④的化学方程式:

①______;

②______;

③______;

④______.

考点:盐的性质设计实验和科学探究化学反应方程式的书写文字表达式化学式的写法和意义
题型:填空题

请你用分子、原子的知识解释生活中的下列现象  

①湿衣服放在太阳晒着的地方容易干  

②热胀冷缩

题型:填空题

阅读理解。

     Have you ever imagined what the world will be like in the near future? A recent study shows that the

world in 2100 will be more crowded, more polluted and less stable ecologically than the world we live in

now. Visible ahead is serious stress involving population, resource and environment. Despite greater food

output, people in the world will be poorer in many ways than they are today.

     For hundreds of millions of the extremely poor, the outlook for food and other necessities of life will

be no better, for many it will be worse.

     While the economies of the developing countries are expected to grow at a faster rate than those of

the industrialized nation, the total national product per head in most less developed countries remains low.

The existing gap between the rich and poor nations will further widen.

     World food production is estimated to increase by 90 percent from 2000 to 2100. Most of that increase

goes to the countries that already have relative higher per-head food consumption. Mean-while, per-head

consumption of food in the developing countries will scarcely improve or will actually fall far below the

present inadequate level. What is worse is that prices for food are expected to double.

     As a result, many less developed countries will have increasing difficulties meeting energy needs. For

the one quarter of mankind that depends primarily on wood for fuel, the outlook is not hopeful.

     Regional water shortage will become more severe. In the 1970-2100 period population growth will

require twice as much water as it does today in nearly half the world. Still greater increases would be needed

to improve standards of living. Development of new water supply will become more costly.

1. According to the passage, in 2100 although output of food will be greater, _____.

A. people will have sufficient food supplies

B. the resource will become more than enough

C. in most developing countries people will have less food than they have today

D. the living standards of the world's population will improve greatly

2. According to the author, in 2100 for many poor people, _____.

A. things will get even worse

B. things will be a little better

C. it will be necessary for them to improve their housing

D. it will be impossible to obtain enough necessities of life

3. In the 2000-2100 period, the large proportion of global increase of food production goes _____.

A. to 90 percent as estimated

B. to any country in the world that needs it

C. to developing countries

D. to those countries that already have high per-head consumption

4. The passage is mainly concerned about _____.

A. the future problems in the world

B. water and air pollution

C. water and food shortages

D. food production and consumption

题型:填空题

下列何经绕肩胛

A.手阳明大肠经

B.手厥阴心包经

C.手太阳小肠经

D.手少阴心经

E.手太阴肺经

题型:填空题

A国甲居民公司在B国设有一分公司。2010年甲公司在A国取得应纳税所得额为100万元适用企业所得税税率为30%。分公司在B国取得应纳税所得额30万元,适用企业所得税税率40%。两国计算应纳税所得额的口径一致,A国税务机构对甲公司征收的2010年企业所得税税额为(100+30)×30%-30×40%=27万元。则A国对甲公司采用的消除国际重复征税的方法是( )。

A.全额免税法

B.直接抵免法中的全额抵免法

C.累进免税法

D.直接抵免法中的限额抵免法

题型:填空题

()是采用专用的发射信号干扰、破坏敌方电子系统正常工作的专用技术

A.电子侦察

B.反电子侦察

C.电子干扰

D.电子反干扰

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