What gas is a human-made pollutant in the lower (surface) atmosphere but a natural and beneficial gas in the stratosphere? (a) CO2 (b) CH4 (c) O3 (d) CFCs (e) N2O Gases: Gases are substances in which part...
Yes, stars die just as humans. They are born. They grow old. And they die when they are out of gas. Most stars are between 1 and 10 billion years old.快乐练习根据短文内容,判断下列句子的正(T)误(F)。() 1. Stars look small because they are far away from us.()2. The sun is ...
Oxygen is the gas that humansand animals breathe.Another planet in the solar system seems to besomething like the earth. That planet is Mars(火星).Mars is smaller than the earth, and it is quite a bit cooler.But it is not too cold for humans. On some days, thetemperatures are as ...
4. D) It is offering a big reward to anyone who helps.5. B) Help people connect with each other.6. C) It does not use volunteers.7. D) They will find they have something in common.8. C) Preparations for Saturday’...
Answer to: In the more highly developed animals, such as humans, what gas is used to regulate the activity of the heart, the blood vessels, and the...
It is widely acknowledged that COVID-19 spreads around the country at an amazing speed and results in enormous loss to humans. Despite this, you are determined to devote yourselves to fighting against the virus in the front line. Knowing h...
15.What is the workshop in the afternoon about? A. Knowledge economy. B. Risk assessment. C. Employee motivation. 16.What does the woman say about her job? A. It can be challenging. B. It is truly interesting. C. It will be rewarding. ...
阅读理解主题:人与自然(环境保护)体裁:说明文话题:如何减少温室体排放What is the single most effective way to reduce greenhouse gas emissions? Go vegetarian? Replant the Amazon? Cycle to work? None of the above. The answer is: make air-conditioners radically better. By one calculation. replacing ...
【题目】What is the single most effective way toreduce greenhouse-gas emissions? Go vegetarian? Replant the Amazon? Cycle to work?None of the above. The answer is: make air-conditioners radically better. On one calculation, replacing refrigerants(制冷剂) that damage the atmosphere would reduce ...
Natural gas is energy collected from fossils and is embedded deep under the surface of the earth. Natural gas was formed centuries when remnants of animals and plants formed broad layers on the earth's surface and were buried. Answer and Explanation:1 ...