问题 问答题 简答题

叶轮给煤机大车行走时打顿,是什么原因?怎样处理?

答案

参考答案:

原因:①蜗轮磨损,啮合打滑;②轨道不平或车轮磨损不均,造成四只车轮与轨道不能同时接触;③叶轮罩壳托板与煤沟底板有严惩摩擦挤碰现象。

处理方法:①更换蜗轮;②轨道找平或更换车轮,使四只车轮与轨道均匀接触;③消除托板与底板间的摩擦挤碰。

填空题
阅读理解

阅读理解。

     How can a creature weighing over 5 tons and normally taking 150 kilograms food and 120 liters of water

per day survive in a desert environment?

     In the southwest African country of Namibia, and the Sahara lands of Mali further north, the desert elephant

does just that.

     Although not regarded as a separate species from the African elephant, the desert cousin differs in many

ways. Their bodies are smaller, to absorb less heat, and their feet are larger for easier walking across sandy

surfaces. They are taller to reach higher branches. They have shorter tusks, and most importantly, longer

trunks to dig for water in riverbeds.

     Desert elephants can travel over 70 kilometers in search for feeding grounds and water holes, and have a

larger group of families. They drink only 3-4 days, and can store water in a "bag" at the back of their throat,

which is only used when badly needed. Desert elephants are careful feeders-they seldom root up trees and

break fewer branches, and thus maintain what little food sources are available. Young elephants may even eat

the dung (粪便) of the female leader of a group when facing food shortage.

     During drought they are unlikely to give birth to their young but with good rains the birthrate will increase

greatly. Desert elephants have sand baths, sometimes adding their own urine (尿) to make them muddy!

     As we continue to overheat our weak planet, it can only be hoped that other animal species will adapt (调

整适应) as extraordinarily well to change as the desert elephant.

1. The underlined part in Paragraph 2 means "_____". [ ]

A. remains in the African countries

B. drinks 120 liters of water a day

C. managed to live in desert areas

D. eats 150 kilograms of food daily

2. Desert elephants are called careful feeders because they _____. [ ]

A. rarely ruin trees

B. drink only every 3-4 days

C. search for food in large group

D. protect food sources for their young

3. The author answers the question raised in the first paragraph with _____. [ ]

A. stories and explanation

B. facts and descriptions

C. examples and conclusion

D. evidence and arguments

4. What can he inferred from the last sentence in the passage? [ ]

A. Overheating the earth can be stopped

B. Not all animal species are so adaptable

C. The planet will become hotter and hotter

D. Not all animals are as smart as desert elephants