问题 问答题 简答题

送煤气操作步骤有哪些?

答案

参考答案:

(1)全面检查煤气设备及管网,确认不漏、不堵、不冻、不窜、不冒、不靠近火源放散,不放入室内煤气,不存在吹扫死角和不影响后续工作进行。

(2)打开末端放散管,监视四周环境变化。

(3)从煤气管道始端通入氮气(或蒸汽)以置换内部空气,在末端放散管附近取样试验,直至含氧量低于2%,关闭末端放散管后停通氮气。

(4)打开煤气管道盲板,再开蝶阀。以煤气置换氮气,在管道末端放散并取样做燃烧试验至合格后关闭放散管。

(5)全线检查安全及工作状况,确认符合要求后,准备生产。

(6)点火,待火焰正常后,关闭末端放散,组织正常生产。

阅读理解

阅读理解。

     Crossing Texas and Mexico, the Big Bend region is high in biodiversity (生物的多样性). It's a place so

untamed that if something doesn't bite, stick, or sting, it's probably a rock.

     You know you have arrived in the heart of the Chihuahuan Desert when it feels as if you have fallen off

the edge of the earth and into the rabbit hole. Nothing is as it appears. Moths (蛀虫) are the size of birds.

Are those twin pillars (柱) of black rock (a landmark known as Mule Ear Peaks) ten miles (16 kilometers)

away or fifty (80 kilometers)? Visibility (能见度) reaches more than a hundred miles on a clear day, and

since there are few roads or buildings to use as milestones, distance is difficult to judge. 

    This is a place where water runs uphill, where rainbows have to wait for rain. The line between myth (虚

构的故事) and reality is unclear. Stare long enough at the Chisos Mountains or the Sierra del Carmen, the

two mountain ranges, known as sky islands, which lie on the land, and they rise and float above the plain.

    The vast Chihuahuan Desert is a land of no people. There is always the chance you'll die of thirst. The

"You Can Die" possibilities are endless, and keep some visitors-350,000 a year to Big Bend National Park,

built in 1944-from coming back. Those who do return are left to think of the remarkable courage of the

brave few who have managed to survive in this terrible environment.

1. The underlined word "untamed" in Paragraph 1 means "_____". [ ]

A. untouched

B. wild

C. unchanged

D. fresh

2. Why do the twin pillars of black rock seem ten or fifty miles away? [ ]

A. They were put so far away.

B. They lie across the Chihuahuan Desert.

C. It is difficult to judge the distance, with few milestones.

D. One lies in the Chisos Mountains, the other in the Sierra del Carmen.

3. How many years are there since the Big Bend National Park was built? [ ]

A. 350,000 years.

B. 350 years.

C. 66 years.

D. 44 years.

4. What is the passage mainly about? [ ]

A. The natural wonders of the Chihuahuan Desert.

B. Everything you see is not what it seems in the Chihuahuan Desert.

C. The terrible environment of deserts in Texas and Mexico.

D. A special place where none who go can return.

5. What can we learn from the last paragraph? [ ]

A. There are all kinds of living things in the Chihuahuan Desert.

B. No people live in the Big Bend region.

C. Nothing is as it appears in the Big Bend region.

D. Traveling in the Big Bend region is dangerous.

填空题