预防管道内燃内爆的措施主要是制止爆管事故的发生

题型:判断题

问题:

预防管道内燃内爆的措施主要是制止爆管事故的发生

考点:输气工考试输气工技师输气工技师题库
题型:判断题

某检修小组乘一辆汽车沿公路东西方向检修线路,约定向东为正,某天从A地出发到收工时行走记录为(单位:千米):

+15、—2、+5、—1、—3、—2、+4、—5

(1)计算收工时,检修小组在A地的哪一边,距A地多远?

(2)若每千米汽车耗油量为0.4升,求出发到收工检修小组耗油多少升?

题型:判断题

某海港拟建两个5万t级泊位重力式沉箱顺岸式结构码头。

对用于基床抛石的石料质量有什么要求?

题型:判断题

不符合成品钢材取样的原则的有()。

A.按规定的位置取样

B.按规定的方向取样

C.钢产品的尺寸和外观合格

D.取样数量随意

题型:判断题

第三部分 阅读理解(共15小题;每小题2分,满分30分)

阅读下列短文,从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

A

Fifty years from now the world’s population will be declining, with no end in sight. Unless people’s values change greatly, several centuries from now there could be fewer people living in the entire world than live in the United States today. The big surprise of the past twenty years is that in not one country did fertility (生育能力) stop falling when it reached the replacement rate(出生率)—2.1 children per woman. In Italy, for example, the rate has fallen to 1.2. In Western Europe as a whole and in Japan it is down to 1.5. The evidence now indicates that within fifty years or so world population will peak at about eight billion before starting a fairly rapid decline.

Because in the past two centuries world population has increased from one billion to nearly six billion, many people still fear that it will keep “exploding” until there are too many people for the earth to support. But that is like fearing that your baby will grow to 1,000 pounds because its weight doubles three times in its first seven years. World population was growing by two percent a year in the 1960s; the rate is now down to one percent a year, and if the patterns of the past century don’t change completely, it will head into negative numbers. This view is coming to be widely accepted among population experts, even as the public continues to focus on the threat of uncontrolled population growth.

As long ago as September of 1974 Scientific American published a special issue on population that described what demographers (人口统计学家) had begun calling the “demographic transition” from traditional high rates of birth and death to the low ones of modern society. The experts believed that birth and death rates would be more or less equal in the future, as they had been in the past, keeping total population stable after a level of 10-12 billion people was reached during the transition.

56. Which of the following statement is NOT true according to the passage?

A. The world’s population in the future will be reducing endlessly.

B. When the earth population reaches 8 billion, it will see a rapid decrease.

C. In modern society the birth and death rates will be more or less equal in the future.

D. The public now pay little attention to the threat of uncontrolled population growth.

57. What’s reason for the sharp increase of world population in the past two centuries?

A. Because people fear that the world will explode.

B. Because the world’s replacement rate keeps falling.

C. Because people’s values has greatly changed.

D. The passage doesn't mention it.

58. The expression “demographic transition” (Paragraph 3) probably means _______.

A. high death rate to the low one

B. high birth rate to the low one

C. high rates of birth and death to the low ones

D. low rates of birth and death to the high ones

59. We can learn from the passage that _______.

A. in the near future there will be a rapid decline of the world population

B. the birth and death rates of modern society will be unequal in the future

C. there would be the same population living in the world than it in the US today

D. in Western Europe the replacement rate has declined to a negative number

题型:判断题

在下列PLC图形符号中,表示电磁执行机构的是()。

A.

B.

C.

D.

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