考研英語閱讀能力提升需要不斷地積累練習，通過多閱讀來積累詞彙，提升閱讀速度，強化把握主旨能力。2017考研複習之初，時間相對充裕，新東方網考研頻道建議大家每天多做一些閱讀，可娛樂也可增長見聞，還能提升能力。下面一篇文章是關於恐龍衰亡的真相。
2017考研英語拓展閱讀：恐龍衰亡的真相
The dinosaurs were already in decline 50 million years before the asteroid strike that finally wiped them out, a study suggests.
一項研究顯示，雖然小行星撞地球是導致恐龍滅絕的原因，但早在五千萬年前恐龍數量已逐步衰減。
The new assessment adds further fuel to a debate on how dinosaurs were doing when a 10km-wide space rock slammed into Earth 66 million years ago.
在人們在爭論恐龍究竟如何躲過6600萬年前那個10km寬的太空隕石撞擊地球時，這項新的評估為這場爭論火上澆油。
A team suggests the creatures were in long-term decline because they could not cope with the ways Earth was changing.
一個研究小組稱，由於不能適應地球的變化，恐龍在很長一段時間內數量衰減。
The study appears in PNAS journal.
這項研究刊登在美國科學院院刊。
Researchers analysed the fossil remains of dinosaurs from the point they emerged 231 million years ago up to the point they went extinct.
研究者對恐龍出現(2.31億年前)直至滅絕期間的恐龍化石進行分析。
To begin with, new species evolved at an explosive rate. But things started to slow about 160 million years ago, leading to a decline in the number of species which commences at about 120 million years ago.
最開始，新物種以爆炸性的速度出現，但1.6億年前這個過程開始放緩，導致在1.2億年前恐龍數量開始減少。
Dr Manabu Sakamoto, a palaeontologist from the University of Reading, who led the research, said: "We were not expecting this result."
英國雷丁大學古生物學家Manabu Sakamoto博士主導這項研究，他說：「我們沒料到是這樣的結果。」
"Even though they were wiped out ultimately by the impact of the asteroid, they were actually already on their way out around 50 million years before the asteroid hit."
「儘管恐龍是由於小行星撞地球而滅絕，但在這之前，即距今約5000萬年前，恐龍已經開始走向衰落。」
Mixed pattern
多重因素作用
Dr Sakamoto’s analysis shows that the long-necked giant sauropod dinosaurs were declining the fastest, whereas theropods, the group of dinosaurs that included the iconic Tyrannosaurus rex, were in a more gradual decline.
Skamoto博士的分析表明，長頸巨型蜥腳類恐龍衰亡速度最快，而獸角類恐龍- 代表性的如雷克斯霸王龍，數量下降緩慢。
Co-author Dr Chris Venditti, an evolutionary biologist from the University of Reading, told BBC News:
來自雷丁大學的演化生物學家、論文聯合作者Chris Venditti博士告訴BBC：
"The current widespread view is that dinosaurs were reigning strong right up to the impact that hit the Earth - and it’s the impact that drove their final extinction," he said.
「目前普遍認為恐龍在小行星撞地球前統治著地球-而小行星撞擊也是導致它們最終滅絕的原因。」他說。
"And while that’s certainly true, what we found was that they were on the decline long before that."
「這當然是事實，但我們發現它們早在那之前就已經走向衰亡。」
Dr Venditti believes that the dinosaurs』 50 million year decline rendered them even more susceptible to the environmental catastrophe that followed the asteroid impact.
Venditti博士認為恐龍在5000萬年前數量的減少導致它們更易受到小行星撞地球過後的環境大災難影響。
"If they were reigning strong perhaps they would have fared much better than they did," he said.
「如果它們數量再多些，可能會更好地適應這種情況。」他說。
A study two years ago also indicated that some species were in decline, but only for the last few million years before the asteroid impact. The new research suggests that the problem began tens of millions of years earlier and affected a wider range of species.
兩年前的一項研究同樣表明，一些物種在衰退，但僅限於小行星撞地球的前幾百萬年。最新研究表明這個問題早在數千萬年前就已經出現，並且對大範圍的物種造成了影響。
So why were the dinosaurs in decline? No one knows but one possibility is an inability to cope with the way the environment was changing.
那麼，恐龍究竟為何會衰亡?沒人知道真正原因，但有一個可能是它們沒有適應環境變化的能力。
Evolutionary pressures
進化壓力
Conditions 230 million years ago were perfect for the dinosaurs when they first emerged, warm and lush from pole to equator.
2.3億年前，恐龍剛出現時，地球環境非常適合它們生存，氣候溫暖，從兩極到赤道動植物繁茂。
But as the climate cooled and sea levels shifted, the dinosaurs may have been subjected to new evolutionary pressures.
但隨著氣候變冷和海平面變動，恐龍可能面臨新的進化壓力。
Dinosaurs and mammals evolved at about the same time, but the former dominated the land surface for more than 100 million years.
恐龍和哺乳動物約在同一時期進化，但前者統治了地球超過1億年之久。
The asteroid impact is commonly thought to have paved the way for mammals to take over. But the new study suggests that mammalian supremacy might have occurred eventually, without a space impact.
人們普遍認為，小行星撞地球為哺乳動物的翻身鋪平了道路。但新的研究表明，即使小行星沒有撞擊地球，哺乳動物最終也會統治地球。
Co-author Prof Mike Benton of Bristol University, told BBC News: "World climates were getting cooler all the time. Dinosaurs rely on quite warm climates and mammals are better adapted to the cold.
論文聯合作者、布裡斯託大學德Mike Benton教授告訴BBC：「全球氣候一直在變冷，恐龍適合在溫暖的氣候條件下生存，而哺乳動物更好地適應了寒氣候。」
"So there might have been a switch over in any case without the asteroid impact."
「因此，無論是否有小行星撞地球，最終哺乳動物都會取代恐龍。」
(責任編輯：田學江)