C.tropical countries have cheaper fruit
D.China prefers to trade with ASEAN countries
72.The best title for this passage is
A.Tariff Cut Boosts Trade
B.Best Ways To Sell Fruits
C.Tropical Fruit To China
D.China Joins ASEAN
E
A summary of the physical and chemical nature of life must begin, not on the earth but in the sun; in fact, at the sun’s very center. It is here that is to be found the source of the energy that the sun constantly pours out into space as light and heat. This energy is liberated at the center of the sun as billions upon billions of nuclei hydrogen atoms clash with each other and fuse together to form nuclei of atoms. The output of light and heat of the sun requires that some 600 million tons of hydrogen be converted into helium(氦) in the sun every second. Thus the sun has been doing for several thousands of millions of years.
The nuclear energy is released at the sun’s center as high-energy gamma radiation, a form of electromagnetic(电磁的) radiation like light and radio waves, only of very much shorter wavelength. This gamma radiation is absorbed by atoms inside the sun, to be remitted at slightly longer wavelengths. This radiation in its turn, is absorbed and remitted. As the energy filters through the layers of solar inner, it passes through the X-ray part of the spectrum(光), eventually becoming light. At this stage, it has reached what we call the solar surface, and can escape into space, without being absorbed further by solar atoms. A very small fraction of the sun’s light and heat is given off in such direction that, after passing unhindered through interplanetary space, it hits the earth.
【高考英语冲刺阅读理解训练题(八)】相关文章:
★ 2017高考四川省广安市英语阅读理解一轮系列训练:22(含解析)
★ 安徽省淮南市2014高考英语一轮单项选择及文章训练(1)及答案
★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (31)
★ 安徽省淮南市2014高考英语一轮单项选择及文章训练(12)及答案
★ 贵州省贵阳市2014高考英语(新人教版)一轮阅读训练(36)附答案
★ 2016届高考英语二轮复习阅读理解七十五十集之连载训练:(28)
★ 湖南省汝城二中2014届高考英语一轮复习阅读训练 (79)
★ 河南省三门峡市2014高考英语一轮(暑假)基础训练(11)附答案
★ 2016届高考英语二轮复习阅读理解七十五十集之连载训练:(30)
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21