C. There is almost no oxygen in the air on Mars. D. Mars is smaller than the E. arth,and it is quite a bit cooler. F. 项不正确。其他三项都与文章相符。 2I.阅读理解AThe earth is the only planet that scientists thinkhas life. Why does the earth have life while the otherplanets(...
The moons of the planets also have their own unique features. Some moons have atmospheres, while others are covered in ice. 1. The sun is the center of the solar system and gives off ___. A. air and water B. light and heat C. rocks and dust D. oxygen and nitrogen 相关知识点: ...
根据第四段中的“There is plenty of water to drink or to live in.”,“The atmosphere has a lot of oxygen in it for animals to breathe,”以及“the temperature is just right for plants, animals, and humans in most places on Earth.”可知生命存在于地球是因为地球上有水,空气和温度。故答...
Mercury was created billions of years ago, when big rocks ran into each other. After these accidents, the planet was frequently visited by meteorites (流星) for several hundred million years. There were also many volcanic eruptions. As the planet cooled, the thin, rocky outside shell reduced ...
“Coal fires are a global disaster,” said Associate Professor Glenn Stracher of East Georgia Collage in Swainsboro, USA. But ___ (54) few people know about them. Coal can heat up on its own, and eventually catch fire and burn, if there is a continuous oxygen supply. The heat produced...
Explain how the melting point can be used to determine whether there are impurities in a solid. What is the boiling point of oxygen? What is molar heat of fusion? In chemistry, what factor is generally responsible for high melting points?
How can liquid form in colder temperatures? Why do we say that a molecule of water is polar? Why is there more water vapor in expired air than inspired air? Explain how oxygen and carbon dioxide are carried by the blood. Why isn't starch soluble in water?
there is waterC. there is oxygenD. there is carbonC3. We can infer from the passage that the final purpose of the space ship is toA. take some soil from the MarsB. search for waterC. search for water, oxygen and carbonD. look for life on the Mars4. According to the passage, ...
Measurement of Intracellular Reactive Oxygen Species (ROS) by Flow Cytometry The dihydrorhodamine 123 assay (DHR 123; Life Technologies Corp. Carlsbad, CA, USA), based on the oxidation of DHR 123 to fluorescent rhodamine 123 by hydrogen peroxide, was used to measure ROS levels in lung leukocyte...
环境监测大题(Environmental monitoring is a big problem).doc,环境监测大题(Environmental monitoring is a big problem) One, two different methods for determining the first type of pollutants in water are described respectively. Determination of mercury;