閱讀部分
詞匯題
| diminish = decrease |
rudimentary=primitive |
| readily=quickly |
hasten = hurry |
| hence=thus |
prolong=extend |
| divert=redirect |
widespread = common |
| excessive e=too much |
controversy=debate |
| strictly aquatic habitat = only live in aquatic environment |
第一篇
題材劃分：環(huán)境類
大部分淡水存在冰川中，可用的地表水只有40%左右。由于人們過度用來灌溉和飼養(yǎng)牲畜，所以地表水愈來愈少。當(dāng)refill跟不上用的速度了，地表水就開始缺乏。地表水層由沙子石頭等組成，水少了以后就開始collapse，出現(xiàn)一些holes，這樣地表水層的空間就更小了。有個400米深的水井，人們就大量使用導(dǎo)致周圍的淺一點地方都沒有水了，人們只能廢棄那些地方。后來又講了一種叫做土地鹽堿化的相關(guān)災(zāi)害對海邊的影響。
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TPO-14 Maya Water Problems
Tpo24 Lake Water
相關(guān)背景資料：
Soilsalinity is the salt content in thesoil; the process of increasing the salt content is known as salinization. Saltsoccur naturally within soils and water. Salination can be caused by naturalprocesses such as mineral weathering or by the gradual withdrawal of an ocean.It can also come about though artificial processes such as irrigation.
Causes of soil salinity
The excess accumulation of salts, typicallymost pronounced at the soil surface, can result in salt-affected soils. Saltsmay rise to the soil surface by capillary transport from a salt-laden watertable and then accumulate due to evaporation. They can also become concentratedin soils due to human activity, for example the use of potassium as fertilizer,which can form sylvite, a naturally occurring salt. As soil salinity increases,salt effects can result in degradation of soils and vegetation.
Salinization as a processcan result from:
-high levels of salt inwater.
-landscape features thatallow salts to become mobile (movement of water table).
-climatic trends that favoraccumulation.
-human activities such asland clearing.
-Irrigation - salt runofffrom streets (in winter if the streets are salted for snow)
第二篇
題材劃分：地質(zhì)類
主要內(nèi)容：火星是否存在生命體
火星探索發(fā)現(xiàn)表面沒有水，減少了有生命的可能。很久以前，一顆火星的隕石飛到了地球的極圈，因為很冷所以能基本無污染的保存下來。科學(xué)家打開來檢查，發(fā)現(xiàn)有種長得像地球遠(yuǎn)古生物(蟲?)的生物，但是其他科學(xué)家說這個結(jié)構(gòu)太小了，不可能有生物的基本功能。還發(fā)現(xiàn)了carbon的元素，這是地球生命產(chǎn)生的必須物質(zhì)，但又有指出說這是地球生物的必須，還是不能證明火星能有生命。
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TPO-8 Running Water on Mars
TPO-41 Climate ofVenus
相關(guān)背景資料：
The current understanding ofplanetary habitability—the ability of a world to develop environmentalconditions favorable to the emergence of life—favors planets that have liquidwater on their surface. Most often this requires the orbit of a planet to liewithin the habitable zone, which for the Sun extends from just beyond Venus toabout the semi-major axis of Mars. During perihelion, Mars dips inside this region,but the planet's thin (low-pressure) atmosphere prevents liquid water fromexisting over large regions for extended periods. The past flow of liquid waterdemonstrates the planet's potential for habitability. Some recent evidence hassuggested that any water on the Martian surface may have been too salty andacidic to support regular terrestrial life.
The lack of a magnetosphereand the extremely thin atmosphere of Mars are a challenge: the planet haslittle heat transfer across its surface, poor insulation against bombardment ofthe solar wind and insufficient atmospheric pressure to retain water in aliquid form (water instead sublimes to a gaseous state). Mars is also nearly,or perhaps totally, geologically dead; the end of volcanic activity hasapparently stopped the recycling of chemicals and minerals between the surface andinterior of the planet.
Evidence suggests that theplanet was once significantly more habitable than it is today, but whetherliving organisms ever existed there remains unknown. The Viking probes of themid-1970s carried experiments designed to detect microorganisms in Martian soilat their respective landing sites and had positive results, including atemporary increase of CO2 production on exposure to water and nutrients. Thissign of life was later disputed by some scientists, resulting in a continuingdebate, with NASA scientist Gilbert Levin asserting that Viking may have foundlife. A re-analysis of the Viking data, in light of modern knowledge ofextremophile forms of life, has suggested that the Viking tests were notsophisticated enough to detect these forms of life. The tests could even havekilled a (hypothetical) life form. Tests conducted by the Phoenix Mars landerhave shown that the soil has a alkaline pH and it contains magnesium, sodium,potassium and chloride. The soil nutrients may be able to support life, butlife would still have to be shielded from the intense ultraviolet light.
第三篇
題材劃分：生物類
主要內(nèi)容：兩棲類動物在沙漠的生存
講的是一種兩棲動物，一個toad—個蝦，如何在沙漠缺水的環(huán)境里生存的。主要是講他們利用很短的濕潤的季節(jié)進行繁殖來維持種族的繁衍;在旱季的時候，通過各種保護行為來生存下來。toad是長期在地下，然后在合適的時候出來產(chǎn)卵繁衍。還說了未成年的應(yīng)對，比如水快沒了的一些應(yīng)對。toad存活率很低，因為缺水的話toad就會長得很小，然后toad內(nèi)部有弱肉強食，外部又有其他捕食者。還講了有水的時候才能活的一種蝦，這種蝦也是在盆地底層一直冬眠很久，直到合適環(huán)境迅速孵化，一般是冬天，因為冬天水會比較多，在十天左右的時間，然后迅速繁衍。
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TPO-40 Amphibian Thermoregulation
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