恐龙为什么会突然灭绝？，本文主要内容关键词为：恐龙论文，此文献不代表本站观点，内容供学术参考，文章仅供参考阅读下载。
Dinosaurs（注：dinosaur[
]n.[古生]恐龙）were reptiles（注：reptile['reptail]n.爬行动物）which became extinct（注：extinct[
]adj.灭绝的，绝种的）about 65 million years ago.The mostintriguing （注：intriguing[
]adj.引起好奇心（或兴趣的））question about dinosaurs hasalways been "why did they die out?"There is no simple answer tothis question,even though many hundreds of scientists arestudying the problem.They are no studying the extinction ofthe dinosaurs alone,but the whole question of extinction.Manyother plants and animals have died out （注：die out 逐渐消失）in the past,and it is important to understand how andwhy this happened.Having this information could help save manyspecies（注：species[
]n.[单复同]种，类）that are under threat in the modernworld.Humans are causing extinctions now,because of pollutionand other damage to the environment.Maybe the dinosaurs cantell us how to save the earth today,because of their extinction65 million years ago! Some of the early dinosaur scientists,100 years ago,thought the dinosaurs died out because theair changed,and they could not breathe.Others thought thatthe dinosaurs disappeared simply because they became too big.They were too heavy to move without falling over,and couldnot find enough food to survive.One theory is that a hugekiller meteorite（注：meteorite[
]n.[天]陨星）hit the earth.Some scientists hold （注：hold[
]vt.认为，相信）that the extinction of dinosaurs was-possibly due to a rapid cooling of the planet's climate.Perhaps huge amounts of lava（注:lava[
]n. [地]熔岩） poured out of volcanoes in India. Thissent up vast clouds of dust that blacked out （注：black out使隔绝，使不起作用）the sun,and made the earth icy cold.
恐龙是爬行动物，早在6500万年前就已灭绝。有关恐龙最引人兴趣的问题一直是：“它们为什么会灭绝呢？”虽然许多科学家一直在研究，但仍未找到简单的答案。科学家们不只是研究恐龙一种动物的灭绝，而是研究“灭绝”这一大课题。在过去，许多植物和动物消失了，而了解它们是怎么和为什么消失是十分重要的，这将有助于抢救在现代世界中濒临灭亡的许多物种。由于污染和其他对环境的破坏，人类在人为地制造物种灭绝。或许了解恐龙6500万年前的灭绝能告诉我们该如何拯救今天的地球！100年前， 有些早期研究恐龙的科学家认为恐龙的灭绝是由于空气变化，以致它们无法呼吸；有些则认为恐龙消失只是因为其体积太大，太重，活动困难，时时跌倒，无法找到生存所需的足够食物。有种理论认为曾经有颗巨大的致命陨星坠落在地球上。还有些科学家认为恐龙可能是由于地球气候骤然变冷而灭绝的。也许印度火山爆发喷放出巨量熔岩，大量尘雾完全遮住了太阳，致使地球变得冰冷。