为起重机供电的同一低压电源系统中,不得出现一部分电气设备采取(),另一部分电气设备却

题型:单项选择题

问题:

为起重机供电的同一低压电源系统中,不得出现一部分电气设备采取(),另一部分电气设备却采取接地保护的情况。

A、过流保护

B、失压保护

C、接零保护

D、偏斜限制器

E、电源断相保护

F、锚定装置或铁鞋

G、超速保护

H、夹轨器

I、过压保护

J、欠压保护

考点:起重机操作证考试起重机械作业人员考试起重机械作业人员考试题库
题型:单项选择题

Section B

Directions: Complete the following passage by using the words in the box. Each word can only be used once. Note that is one word more than you need.

A.recovery

B.images

C.instant

D.blame E.shockingF.accuracy  G.concentrate  H.awarded  I.fined   J.estimate

Think you can walk, rive, take phone calls, email and listen to music at the same time? Well, New York’s new law says you can’t. and you I’ll be  41  $100 if you do it on a New York City street.

The law went into force last year, following recent research and a (n)  42  number of accidents that involved people using electronic devices when crossing the street.

Who’s to  43  ? scientists say that our multitasking(处理多重任务的)abilities are limited.

“We are under the impression that our brain can do more than it often can ,” says Rene Marois, a scientist in Tennessee. “But a major limitation is the inability to  44  on two things at once.”

The young are often considered the great multitaskers. However, an Oxford University research suggests this idea is open to question. A group of 18-to 21-year-olds and a group of 35-to 39-year-olds were given 90 seconds to translate  45  into numbers, using a simple code. The younger group did 10 percent better when not interrupted. But when both groups were interrupted by a phone cal or a (n)   46 message, the older group matched the younger group in speed and  47  .

It is difficult to measure the productivity lost by multitaskers. But it is probably a lot. It is estimated that the cost o interruptions to the American economy is nearly $650 lillion a year.

The   48  is based on surveys with office workers. The surveys conclude that 28 percent of the workers’ time was spent on interruptions and   49  time before they returned to their main tasks.

题型:单项选择题

冶金焦的产量占()的百分比称冶金焦率。

题型:单项选择题

应当尽量利用()的防、排烟系统和移动排烟设备进行防烟、排烟。

题型:单项选择题

对造成环境污染为主的建设环境影响评价,其项目工程分析的重点是( )。

A.资源、能源的储运

B.场地的开发利用

C.工艺过程

D.交通运输

题型:单项选择题

《慈善法》对慈善组织负责人的任职资格作了限制性规定,下列人员中,不得担任慈善组织的负责人是()。

A.20岁大学生,患有轻度间歇性失忆症

B.三年前被吊销营业执照的私营业主老王

C.18岁的小张两年前因盗窃入狱,现已刑满释放

D.60岁工厂退休职工,精神很好但是因中风腿脚不便

更多题库