在使用逼近法铣削非圆弧曲线时,所加工零件的精度取决于()。 A.逼近方式 B.节点密

题型:单项选择题

问题:

在使用逼近法铣削非圆弧曲线时,所加工零件的精度取决于()。

A.逼近方式

B.节点密度

C.逼近方式和节点密度

D.曲线形状

考点:铣工考试数控铣工(综合练习)数控铣工(综合练习)题库
题型:单项选择题

不属于大气污染对健康直接危害的是

A.慢性中毒

B.变态反应

C.急性中毒

D.肺癌

E.佝偻病

题型:单项选择题

阅读理解。

     All of us eat every day, but most of us don't understand the study nutrition(营养).We often make

mistakes in talking about how to keep a good diet.

     For example, many people think that food such as rice, bread, and potatoes will make one fat, this kind

of food is very good for one's health. It's good source of many vitamins and it contains less amount of

calories. Some people don't like frozen vegetables, because they think fresh vegetables cooked at home are

always better. This is wrong again. In fact, whether the vegetables are good or not depends more on how

they prepared. Overcooking, for example, destroys many good qualities of vegetables. Vegetables cooked in

 too much water can lose a deal of vitamins.

     It is also wrong to say that vegetables grown in poor, worn-out soil are lower in vitamins than vegetables

grown in rich soil. The vitamins are in the plants themselves. They don't come from the soil. However the

minerals(矿物质)in a plant depend on the minerals in the soil.

     In short, there are many wrong ideas about nutrition. We need to correct them.

1. The passage is mainly about ______ .

A. nutrition

B. vitamins

C. vegetables

D. health

2. Rice, bread and potatoes are good for people's health mainly because ______.

A. they make people fat

B. there are a lot of vitamins in them

C. they contain more calories

D. they give people more heat

3. Why don't some people like frozen vegetables?

A. They think fresh vegetables contain fewer vitamins

B. They think fresh vegetables contain a lot of vitamins

C. They don't think the frozen vegetables are flesh

D. They don't think the frozen vegetables taste as good as the fresh ones.

4. Which of the following is true according to the passage?

A. Many people know almost everything about nutrition.

B. Food such as rice, bread, and potatoes make people fat.

C. The minerals in a plant do not come from the soil

D. Vegetables grown in poor soil may have the same amount of vitamins as those grown in rich.

5. In this passage the writer wants to tell us that ______.

A. people should correct wrong ideas about good diet

B. vegetables should be cooked in too much water

C. why people don't like frozen vegetables

D. rice, bread and potatoes can make people fat

题型:单项选择题

自动变速器EC.U主要根据()等信号,计算相应的主油路油压值,并通过输出相应的占空比脉冲电压来控制油压调整电磁阀(脉冲式电磁阀)的开、关比率,实现对主油路油压的调控。

A.节气门的开度

B.档位

C.自动变速器油温度

D.换档

题型:单项选择题

人力资源培训的内容包括:知识培训、技能培训和态度培训()

题型:单项选择题

可用作静脉脂肪乳的乳化剂是()

A.卵磷脂

B.吐温80

C.阿拉伯胶

D.十二烷基硫酸钠

E.明胶

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