把12：5的后项加10，要使比值不变，前项应加（ ） A．10 B．12 C．24 D．

阅读理解。

     Many facts suggest that children are overweight and the situation is getting worse, according to the doctors.

I feel there arc a number of reasons for this.

     Some people blame the fact that we arc surrounded (包围) by shops selling unhealthy, fatty foods, such as

fried chicken and ice cream, at low prices. This has turned out a whole generation of grown-ups who seldom

cook a meal for themselves. If there were fewer of these restaurants, then probably children would buy less

take-away food.

     There is another argument that blames parents for allowing their children to become overweight. I agree with

this, because good eating habits begin early in life, long before children start to visit fast food shops. If children

are given fried chicken and chocolate rather than healthy food, or are always allowed to choose what they eat,

they will go for sweet and salty foods every time, and this will carry on throughout their lives.

     There is a third reason for this situation. Children these days take very little exercise. They do not walk to

school. When they get home, they sit in front of the television or their computers and play computer games. Not

only is this an unhealthy pastime (消遣), it also gives them time to eat more unhealthy food. What they need is

to go outside and play active games or sports.

     The above are the main reasons for this problem, and therefore we have to encourage young people to be

more active, as well as steering them away from fast food shops and bad eating habits.

1. According to the text, what kind of children may eat more unhealthy food?

A. Those who often take exercise.

B. Those who often watch television.

C. Those who often have meals at home.

D. Those who often walk to school.

2. The author thinks that children are becoming overweight because _____.

A. their parents often cook meals for them

B. they are too busy to go out and play

C. they can't choose what to eat

D. there are too many fast food shops around

3. The word "steering" underlined in the last sentence most probably means _____.

A. forcing

B. guiding

C. driving

D. moving

4. The main purpose of the text is to _____.

A. tell a story

B. provide facts

C. give advice

D. compare opinions

估算的准确度应能满足建设项目决策（）的要求。

A.分析阶段

B.策划阶段

C.实行阶段

D.各个阶段

下列化合物是挥发油的为（）

A.环烯醚萜、脂肪族、芳香族

B.脂肪族、芳香族、萜类

C.生物碱、环烯醚萜、芳香族

D.脂肪族、芳香族、皂苷

E.香豆素、芳香族、萜类

对首次采用的金属材料或焊接材料应进行（），其结果应符合设计要求和国家标准的有关规定。

A、评估

B、焊接工艺评定

C、焊接

D、设计

黄金市场监管应当遵循哪些原则？