要參加托福考試的同學們，出國留學網(wǎng)為你整理“2017年托?？荚嚲x作文(3)”，供大家參考學習，希望廣大放松心態(tài)，從容應對，正常發(fā)揮。更多資訊請關(guān)注我們網(wǎng)站的更新哦!
2017年托?？荚嚲x作文(3)
菊石是因為小行星撞擊后的一系列影響而滅絕的
一種叫ammonite的已滅絕生物，大致的原因是隕石撞擊
閱讀給出的三種觀點：
隕石撞擊導致這種生物暴露在酸雨之下，導致young ammonite be killed off后代也死亡
zooplankton作為ammonite的主要食物來源，隕石撞擊導致海洋溫度驟降，這種植物大量減少，導致ammonite因為缺少食物而滅絕
ammonite因為缺少氧氣而無法在海洋里生存
聽力逐一反駁：
舉frogs的例子，同樣是生活在水里，卻沒有被酸雨影響導致滅絕，所以ammonite的滅絕無法被證實是酸雨導致的
ammonite有許多groups，并不是所有種類的ammonite都以zooplankton為食
有一種種類的ammonite擁有在氧氣不足的環(huán)境中也能生存下來的器官
最新托福綜合寫作范文：
The reading and listening both talk about whether the Ammonites died out due to asteroid apocalypse. However, the lecturer lists three reason to contradict what the passage indicates.
First, according to the lecturer, if the acid rains had killed off the ammonites on the surface of the water, another kind of frog, which also lived near the ocean, would become extinct as well. However, they still exist till now. Thus, the acid rain caused by asteroid impact mentioned in the reading passage was not the main reason.
Secondly, the reading passage indicates that the disappearance of zooplankton, which was the main food of ammonites, directly cause the extinction of them. However, zooplankton was just a small part of their food supply, according to professor, only a part of ammonites lived on zooplankton. Therefore, zooplankton didn’t account for that.
As to the third reason of absence of oxygen, the professor claims that the special physical structure allowed ammonites to live with hypoxia, which means that the statement in the reading that the impact taking away oxygen from the atmosphere killed all of ammonites is not correct.(185words)