台中托福補習班推薦英語蛋

這裡就考驗學生對文章中心框架的把握。結合文章標題和題目的引導句來判斷文章主旨，非常重要的一點是，我們要充分利用前面做過的題目。我們在前面的做題中已經對各個段落的主旨有了一個大致的瞭解。段落主旨可以直接看段首句，段首句通常是段落的主旨句。　　

正確選項是一些總結性的選項，錯誤選項的特點是：與原文不符，原文沒有提到，或者是次要資訊。次要資訊也就是文中提到的某個細節性的資訊，次要資訊的選項具有極大的干擾，同學們在做題時應注意識別。

Paragraph 1:

Cases in which many species become extinct within a geologically short interval of time are called mass extinctions. There was one such event at the end of the Cretaceous period (around 70 million years ago). There was another, even larger, mass extinction at the end of the Permian period (around 250 million years ago). The Permian event has attracted much less attention than other mass extinctions because mostly unfamiliar species perished at that time.

　　Q： Paragraph 1 supports which of the following statements about mass extinctions?

　　A. They take place over a period of 70 million years.

　　B. They began during the Cretaceous period.

　　C. They eliminate（消滅） many animal species that exist at the time they occur.

　　D. They occur every 250 million years.

　Ø解析：段落第一句話以mass extinctions做關鍵字，定位第一句，說大量生物在短時間內滅絕的這種現象叫做大滅絕事件，選項C是原文的同義替換，所以是正確答案。

Paragraph 3:

 What could cause such high rates of extinction? There are several hypotheses, including warming or cooling of Earth, changes in seasonal fluctuations or ocean currents, and changing positions of the continents. Biological hypotheses include ecological changes brought about by the evolution of cooperation between insects and flowering plants or of bottom-feeding predators in the oceans. Some of the proposed mechanisms required a very brief period during which all extinctions suddenly took place; other mechanisms would be more likely to have taken place more gradually, over an extended period, or at different times on different continents. Some hypotheses fad to account for simultaneous (同時發生) extinctions on land and in the seas. Each mass extinction may have had a different cause. Evidence points to hunting by humans and habitat destruction as the likely causes for the current mass extinction.

　　Q：Paragraph 3 supports which of the following ideas about mass extinctions?

A. Scientists know the exact causes of most mass extinctions.

B. Mass extinctions are unlikely to happen again in the future.

C. Insects, flowering plants, and bottom-feeding predators in the oceans tend to be the first organisms to disappear during episodes of mass extinctions.

D. Some mass extinctions occurred on land and in the seas at the same time.

　　Ø解析： 選項D的land and seas做關鍵字定位至倒數第三句，simultaneous就是at the same time

主旨就是對全文內容的總結，考察的是對文章主旨和段落主旨的把握能力。在對題目有了充分的瞭解後，加上掌握了恰當的方法，不會對同學們造成很大障礙的。