Question

15．A wood fire can be handy when you're camping．You can roast marshmallows or stay warm，for example．Forest fires that rage out of control，however，are a big problem．
Wildfires cause hundreds of millions of dollars in damage every year．And the amount of destruction has grown over the last 2 decades，especially in the western United States．
To understand better why the northern Rocky Mountains region has been hit especially hard by wildfires，scientists from the University of Arizona in Tucson looked at weather，snow，and fire records from 1970 to 2003．^
Their study showed that，between 1987 and 2003，fires burned an area 6.5 times larger than the area burned between 1970 and 1986．The fire season also started earlier-，and its average length increased by 78 days．
Warmer spring and summer temperatures appear to be part of the explanation for this change．The average temperature in the study's more recent period was 0.871 higher than it was in the earlier period．And this trend is likely to continue．Experts predict that average summer temperatures may rise between 2¾and 5¾by the year 2050 in western North America．‘
Hie timing of snowmelt appears to be another cause of the fire boom．When snow melts early in the season，forests become drier through the summer and catch fire and burn more easily．Western snow packs now typically melt a week to a month earlier than they did 50 years ago，according to recent studies．
Some people have blamed the growing fire risk on policies that allow bush and branches to build up on forest floors．But clearing bush by itself won't help much if changes in climate are largely responsible for increasingly severe forest fires．
43．The main purpose of studying the records from 1970 to 2003 was toD．
A．find out solutions to forest fires
B．prevent wildfires from happening frequently-
C．know more about the climate changes in the past decades
D．find out the causes of wildfires in the northern Rocky Mountains region
44．Scientists fix＞m the University of Arizona found out the following EXCEPTD
A．western snow packs melt earlier than they did 50 years ago
B．fires burned larger area between 1987．a(chǎn)nd 2003 than between 1970 and 1986
C．the fire season between 1987 and 2003 was longer than that between 1970 and 1986
D．the average summer temperature will be I⁹C and 5¾higher by 2050 than it is now
45．Which of the following statements will Scientists from the University of Arizona agree to？C
A．More wildfires lead to the trend of global warming．
B．Hot summers have nothing to do with the increasing wildfires．
C．The earlier snow melts，the more probably forest fires will happen．
46．Clearing bush will help control the increasingly severe forest fires．What is the main idea the author aims to express in the passage？C
A．The damages caused by wildfires．
B．The results of a study on wild fires．
C．The causes of fires in the United States．
D．The changes in climate in the western United States．

Answer 1

分析 本文是一篇科教類閱讀，主要介紹了通過研究1970-2003年美國的天氣、雪及火災(zāi)記錄解釋了美國洛基山地區(qū)成為火災(zāi)重創(chuàng)區(qū)的一些原因．

解答 43-46．DDCC
43題答案：D考查細節(jié)推理，根據(jù)第二段的To understand better why the northern Rocky Mountains region has been hit especially hard by wildfires…"為了更好地理解為什么洛基山北部尤其受到火災(zāi)的重創(chuàng)…"可知本題答案為D選項．
44題答案：D考查細節(jié)推理，根據(jù)原文第三段的Experts predict that average summer temperatures may rise between 2¾and 5¾by the year 2050 in western North America．"專家預(yù)測北美西部夏季的平均溫度在2050年會上升2%至5%"可知這只是專家的預(yù)測，而并非發(fā)現(xiàn)；故本題答案為D選項．
45題答案：C考查細節(jié)推理，根據(jù)原文倒數(shù)第二段的When snow melts early in the season，forests become drier through the summer and catch fire and burn more easily．雪融化得越早，森林在整個夏季變得更加干燥而且更容易著火燃燒．可知本題答案為C選項．
46題答案：C考查主旨大意，本文主要介紹了通過研究1970-2003年美國的天氣、雪及火災(zāi)記錄解釋了美國洛基山地區(qū)成為火災(zāi)重創(chuàng)區(qū)的一些原因；故本題答案為C選項．

點評 本文是一篇科教類閱讀，題目涉及多道細節(jié)理解題，做題時結(jié)合原文和題目有針對 性找出相關(guān)語句進行仔細分析，結(jié)合選項選出正確答案．推理判斷也是要在抓住關(guān)鍵句子的基礎(chǔ)上合理的分析才能得出正確的答案．