18. 恐龙灭绝和行星撞地球
Iridium, a hard, whitish metal similar to platinum, is extremely rare on Earth. Extremely high concentrations of iridium on Earth result from only two scenarios: massive volcanic eruptions that release iridium from deep within the Earth and meteorites that shower down on Earth from space. When scientists found concentrations of iridium 30 times higher than normal in rock stratum from 65 million years ago, they concluded that a massive meteor or comet hit the Earth and caused the massive extinction of the dinosaurs.
Which of the following, if true, most strongly supports the scientists conclusion?
A. Volcanoes massive enough to generate high concentrations of iridium are very rare.
B. Massive volcanic eruptions occurred frequently 80 million years ago.
C. Most scientists support the hypothesis that a cosmic impact wiped out the dinosaurs.
D. The massive extinction that occurred 70 million years ago killed not only the dinosaurs but also 70 percent of all life on Earth.
E. A comet struck the earth some 120 million years ago, but no widespread extinction occurred.
浪漫英文情书精选:Be In My Heart在我心中
啊,我讨厌英语 Gullia Oops Jaime Pas Langlais 这首歌是不是也唱出你的心声了
精美散文:感悟幸福
精选英语美文阅读:爱他就把他留下来 (双语)
浪漫英文情书精选:Is It Love?这是爱么?
献给女性:如果生命可以重来
精选英语散文欣赏:爱的限度就是无限度地去爱
美文美诗:仙女对牧羊人的回答
精选英语美文阅读:A Friend's Prayer 朋友的祈祷
精选英语美文阅读:无雨的梅雨天 (双语)
精美散文:27岁的人生
浪漫英文情书精选:Let Dream Come True让美梦成真
Love Your Life 热爱生活
铅笔与橡皮的的故事
精选英语美文阅读:公务员的无助
诗歌:永远向前(双语)
双语美文:在思考中成长
浪漫英文情书精选:Starting Over Again重新来过
精选英语美文阅读:木鱼声声
精选英文情诗:请允许我成为你的夏季
精美散文:抬起头来 希望就在眼前
精选英语美文阅读:十字路口的抉择
浪漫英文情书精选:To Be Close To You Again再次靠近你
精选英语美文阅读:在你的镜头前,我总是很美
精选英语美文阅读:初吻 The First Kiss (双语)
浪漫英文情书精选:To Prince Perfect献给心中的王子
双语美文:I Wish I Could believe
精选英语美文阅读:朋友的祈祷
席慕容诗一首:青春 英汉对照
浪漫英文情书精选:The Warmth Of Your Love爱的温暖
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |