若某管子的外径为57mm,壁厚为3mm,则管子的规格型号可表示为()。A.Φ50×3

题型:单项选择题

问题:

若某管子的外径为57mm,壁厚为3mm,则管子的规格型号可表示为()。

A.Φ50×3

B.Φ51×3

C.Φ57×3

D.Φ57

考点:采气工考试采气中级工考试采气中级工考试题库
题型:单项选择题

随着生活水平的提高,人们更加关注食品的营养与安全。下面是某优质火腿肠包装上的部分说明,请分析解答下列问题:

(1)在购买火腿肠时,从食品安全的角度考虑应首先关注包装说明上的________。

(2)为了防止食品腐败,火腿肠一般都采用真空包装,如果误食了包装已鼓胀的火腿肠会引起_______。

(3)从配料中看出:火腿肠含有__________,它是构成人体细胞的基本物质,该物质在人体内最终消化成的产物是___________。

(4)为了增加营养在食品中添加一种或几种营养素,可以预防一些群体性疾病的发生。如在食盐中加碘可以有效地预防______________的发生;铁强化酱油的推广使儿童___________发病率明显下降。

题型:单项选择题

In meditation(冥想),people sit quietly and focus their attention on their breath .As they breathe in and out ,they attend to their feelings .As thoughts go through their minds. They let them go. Breathe .Let go .Breathe .Let go .

According to a recent study at the Insight Meditation Society in Barre,Massachusetts. Three months of training in this kind of meditation causes a market change in how the brain allocates(分配) attention. It appears that the ability to let go thoughts that come into mind frees the brain to attend to more rapidly changing things and events in the outside world. Expert mediators are better than other people at catching such fast-changing stimuli( 刺激),like facial expressions.

The study provides evidence for changes in the workings of the brain with mental training. People can learn and improve abilities of all sorts with practice, everything from driving to playing the piano. The study has shown that meditation is good for the brain. It appears to reduce pressure and promote a sense of well-being.

In an experiment, 17 volunteers with no meditation experience in the experimental group spent three months meditating 10 to 12 hours a day .A control group also with no meditation experience meditated for 20 minutes a day over the same period .Both groups were then given the tests with two numbers in a group of letters. As both group looked for the numbers , their brain activity was recorded.

Everyone could catch the first number .But the brain recordings showed that the less experienced mediators tended to grasp the first number and hang onto it, so they missed the second number .Those with more experience gave less attention to the first number .as if letting it go ,which led to an increased ability to grasp the second number ,This shows that attention can change with practice.

Just ask Daniel Levision , who meditated for three months as part of the study .”I am a much better listener,” he said . “ I do not get lost in my own personal reaction to what people are saying.”

小题1: The underlined word “them” in Paragraph 1 refers to  __________  .

A. feelings

B.minds

C.people

D.thoughts小题2:  Meditations manage their daily tasks better because they   ________  .

A.are given less pressure

B.allocate their attention better

C.have more stimuli for life

D.practice them more frequently小题3:In the experiment ,volunteers doing meditation for longer hours   _____  .

A.were more likely to catch both of the members

B.were used to memorizing numbers in groups

C.usually ignored the first number observed

D.paid more attention to numbers than to letters小题4: The study proves that     _____ .

A.meditation improves one’s health

B.brain activity can be recorded

C.human attention can be trained

D.mediators have a good sense of hearing

题型:单项选择题

在CIF贸易术语下,下列叙述正确的是()。

A.CIF价格,即成本加运费加保费价

B.保险范围不包括特定行业或买方所需的特种险

C.货物在装运港装船前后的保险均由卖方办理

D.卖方负责投保战争险

E.CIF价格又称到岸价格

题型:单项选择题

()颜色模式是一种最佳的印刷模式。

A.RGB

B.位图

C.索引

D.CMYK

题型:单项选择题

机务段内的线路属于()。

A.岔线

B.段管线

C.特别用途线

D.其他线路

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