20.We experience different forms of the Sun's energy every day.We can see its light and feel its warmth.The Sun is the major source of evaporation (蒸發(fā)) of water from the oceans and lakes.Sunlight also provides the energy used by green plants to make their own food.These green plants then provide food for all organisms (生物) on the Earth.
Much of the energy that comes from the Sun never reaches the Earth's surface.It is either reflected or absorbed by the gases in the upper atmosphere.Of the energy that reaches the lower atmosphere,30% is reflected by clouds or the Earth's surface.The remaining 70% warms the surface of the planet,causes water to evaporate,and provides energy for the water cycle and weather.Only a tiny part,approximately 0.023%,is actually used by green plants to produce food.
Many gases found in the atmosphere actually reflect heat energy escaping from the Earth's surface back to the Earth.These gases act like the glass of a greenhouse in that they allow energy from the Sun to enter but prevent energy from leaving.They are therefore called greenhouse gases.
When sunlight strikes an object,some of the energy is absorbed and some is reflected.The amount reflected depends on the surface.For example,you've probably noticed how bright snow is when sunlight falls on it.Snow reflects most of the energy from the Sun,so it contributes to the low temperatures of winter.Dark-coloured surfaces,such as dark soil or forest,absorb more energy and help warm the surrounding air.
64.According to the passage,the root cause for weather changes on the Earth isC.
A.the atmosphere surrounding the Earth
B.water from oceans and lakes
C.energy from the Sun
D.greenhouse gases in the sky
65.Only a small part of the Sun's energy reaches the Earth's surface because most of itC.
A.a(chǎn)bsorbed by the clouds in the lower atmosphere
B.reflected by the gases in the upper atmosphere
C.lost in the upper and lower atmosphere
D.used to evaporate water from the oceans and lakes
66.We learn from the passage thatA.
A.a(chǎn)ll living things on the Earth depend on the Sun for their food
B.a(chǎn) forest looks dark in winter because it absorbs solar energy
C.only 0.023% of the energy from the Sun is made use of on the Earth
D.greenhouse gases allow heat energy to escape from the Earth's surface.
分析 本文屬于說明文閱讀,作者通過這篇文章主要向我們描述了太陽對我們的重要作用,仔細講述了太陽光對地球的影響等信息.
解答 64.C.細節(jié)理解題,根據(jù)第一段The Sun is the major source of energy for our planet可知,地球上天氣變化的根源在于太陽能;故選C.
65.C.細節(jié)理解題,從文章第二段Much of the energy that comes from the Sun never reaches the Earth's surface可知,太陽能只有小部分才能到達地表,大多被表層大氣所反射或吸收.只有B項才概括全面.其中l(wèi)ose一詞用的恰到好處,可以涵蓋reflect和absorb之意.故選C.
66.A.推理判斷題,從文章第一段Sunlight also provides the energy used by green plants to make their own food.These green plants then provide food for all organisms(生物) on the Earth可知,地球上所有生物均要依靠太陽能來間接為他們提供食物.故選A.
點評 本文是一個科教類閱讀,題目涉及多道細節(jié)理解題,做題時結(jié)合原文和題目有針對性的找出相關(guān)語句進行仔細分析,結(jié)合選項選出正確答案.推理判斷題也是要在抓住關(guān)鍵句子的基礎(chǔ)上合理的分析才能得出正確答案,切忌胡亂猜測,一定要做到有理有據(jù).