问题 填空题

人们的日常生活离不开金属.高科技新材料的开发和应用也需要金属.

(1)地壳中含量最高的金属元素是 _________

(2)锂电池是一种新型的高能电池.其质量轻,电容量大.颇受手机、手提电脑等制造商的青睐.某种锂电池的总反应式为Li+MnO2==LiMnO2,其中化合价发生变化的元素是 _________

(3)根据下图金属应用实例推断,金属具有的物理性质有: _________

(4)日常使用的金属材料多数属于合金,下表列出了一些常见合金的主要成分和性能.

由上表推断,与组成合金的纯金属相比,合金的优点一般有(填序号)_________

①强度更低  ②硬度更高③熔点更高④抗腐蚀性更好

(5)人们每年要从金属矿物资源中提取数以亿吨计的金属.根据所学化学知识,按要求写出一个生成金属的化学方程式: _________

(6)2008年奥运会主运动场“鸟巢”使用了大量的钢铁.钢铁与 _________ 直接接触容易生锈造成损失.在钢铁表面涂油、刷漆等,都能防止钢铁生锈.

答案

(1)铝(Al);

(2)Li、Mn

(3)导电性、延展性、导热性

(4)②④;

(5)2CuO+C2Cu+CO2

(6)空气和水.

句型转换

阅读理解

     Singing are the pupils of the remote Beau-Roc primary school in Haiti. One of them plays a guitar

made from an empty oil tin. Their headmistress, Emile Jean-Noel, is one of the few women school

principals in the country.

     Over 70 % of Haitian population live below the poverty line with inadequate food, water, schools,

or housing. To reduce the hunger that prevents learning and to encourage parents to send their children

to school, meals are provided by the World Food Programme.

     "We are so cut off we have many difficulties," comments Emile, adding that finding chalk, school

books and other materials is practically impossible. Emile tries to encourage those around her to make

use of all available resources. Her efforts are bearing fruit. One of her successes was convincing local

women to contribute to their children's schooling and increase their own income by selling embroidery

(刺绣) and other handicrafts.

     Recent political instability has meant that the country has not invested in education for ten years.

Enrolment(入学) is a mere 44 per cent and a little less than a half of those entering primary school finish

it. Less than a third of these go on to secondary school. In rural areas it is not rare to find 17- and

18 year-olds in primary school. Beau-Roc has only 4 teachers for 260 pupils. Emile works constantly

 to improve her pupils'environment. Under her direction, a local worker is now constructing a storehouse

for the food delivered regularly by the World Food Programme.

     Not only is Emile's salary too little, but she receives it irregularly. For her, transport is a real headache. She lives five kilometers away and has to take a privately-owned bus, costing more than she can afford.

     "The decision to be a rural teacher in Haiti should not be taken lightly", Emile comments. "With all the

sacrifices and risks it requires, only those who are really cut out for teaching should do it." Nevertheless,

Emile loves her job. "I always feel at home with the children and, the parents understand what I'm doing."

1. What theme is presented in this passage?

A. Devotion to education.

B. Poverty and hardship.

C. Politics and children  

D. Love and beauty

2. Which of the following is extremely difficult for Beau-Roc primary school?

A. Teaching the women how to make embroidery and other handicrafts.

B. Persuading local women to care about their children's education.

C. Encouraging those around her to use those available resources.

D. Finding chalk, school books and other materials.

3.  In the last paragraph, "those who are really cut out for teaching" are those who are ________.

A. dismissed from teaching

B. unfamiliar with teaching

C. qualified for teaching

D. cautious about teaching

单项选择题