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看題，確定解題和閱讀策略：

1. Which of the following best describes the function of the highlighted sentence??句子功能

2. The author mentions “natural trends” most likely in order to ?信息目的

這兩題都是結(jié)構(gòu)題，更多考察信息關(guān)系，閱讀過(guò)程中可以弱化內(nèi)容。理想狀態(tài)下，可以只看局部信息關(guān)系來(lái)解題。

文章講解：

①Scientific consensus is that humans first began to have a warming effect on Earth’s climate within the past century, after coal-burning factories, power plants, and motor vehicles began releasing carbon dioxide (CO2) and other greenhouse gases in significant quantities into the air. ②However, evidence suggests that human agricultural activities may have had such an effect much earlier: concentrations of CO2?started rising about 8000 years ago, even?though?natural trends?indicate they should have been dropping; methane levels rose similarly about 3,000 years later.?③Without these rises, however, current temperatures in northern parts of North America and Europe would be cooler by three to four degrees Celsius—enough to inhibit agriculture—and an ice age would probably have begun several thousand years ago in northeastern Canada.

1. Which of the following best describes the function of the highlighted sentence?句子功能

A. It?undermines?the assumption that human activity has had a?significant impact?on Earth’s climate 常錯(cuò)干擾選項(xiàng)。沒(méi)有證據(jù)/相反，比較點(diǎn)不是影響，而是時(shí)間

B. It?supports?the assumption that Earth’s temperatures have?risen appreciably?over the past 100 years 句子屬性相反/沒(méi)有證據(jù)

C. It questions the assumption that greenhouse gases have had a warming effect on Earth’s climate?沒(méi)有證據(jù)，不是討論“有沒(méi)有”，而是在說(shuō)“早晚”，所以缺少時(shí)間維度，同A

D. It challenges the assumption that human activity began to affect Earth’s climate after the?advent of industrialization?關(guān)注同義替換

E. It?supports?the assumption that greenhouse gases are a?directby-product?of industrial activities 句子屬性相反/沒(méi)有證據(jù)

?

2. The author mentions “natural trends” most likely in order to?信息目的

A. propose a possible explanation for why?current temperatures in North America and Europe are?not?as low as they might otherwise be?相反/無(wú)關(guān)

B. explain why levels of?methane?in Earth’s atmosphere began to rise approximately 5,000 years ago?沒(méi)有證據(jù)/無(wú)關(guān)

C. suggest that Earth’s climate would have become even?warmer?without the advent of human agricultural activities?沒(méi)有證據(jù)/無(wú)關(guān)/相反

D. identify factors that may have?contributed?to the rise of greenhousegases in Earth’s atmosphere approximately 8,000 years ago and again some 3,000 years later?無(wú)關(guān)/沒(méi)有證據(jù)/相反

E. support the claim that human activity may have played a role in the rise in CO2?and methane levels in the atmosphere thousands of years ago

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