Unit 4 Global warming
课时作业
Ⅰ.阅读理解
(2024·浙江高考)California has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor (因素)．
The number of trees larger than two feet across has declined by 50 percent on more than 46,000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent; in parts of southern California the decline was nearly 75 percent.
Many factors contributed to the decline, said Patrick McIntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left California forests crowded with small trees that compete with big trees for resources (资源)．
But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, McIntyre and his colleagues documented a widespread death of big trees that was evident even in wildlands protected from woodcutting or development.
The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed, taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt (融雪)．
Since the 1930s, McIntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt, which reduces the water supply available to trees during the dry season.
篇章导读：本文是一篇议论文。文章以加利福尼亚的大树从20世纪30年代以来大量减少为主题，探讨出这一现象的原因。
1．What is the second paragraph mainly about?
A．The seriousness of big-tree loss in California. B．The increasing variety of California big trees. C．The distribution of big trees in California forests. D．The influence of farming on big trees in California.
答案：A 主旨大意题。第二段中通过列举一系列数字表明，加利福尼亚州的大树减少的严重性，故A项正确。
2．Which of the following is well-intentioned but may be bad for big trees? A．Ecological studies of forests. B．Banning woodcutting.
C．Limiting housing development. D．Fire control measures.
答案：D 推理判断题。文章第三段提到了造成加利福尼亚州的大树减少的三个因素：woodcutters，housing development与aggressive wildfire control。前两个因素直接与大树的减少有关，如果能控制住，大树就不会减少；而第三个因素——控制野火的措施使得加利福尼亚州的森林里满是跟大树争夺资源的小树，初衷是为了控制野火，这是好的，实则对大树不利，故D项正确。
3．What is a major cause of the water shortage according to McIntyre? A．Inadequate snowmelt. B．A longer dry season. C．A warmer climate. D．Dampness of the air.
答案：C 细节理解题。根据文章最后一段中的“... the biggest factors driving up water stress in the state have been rising temperatures ...”可知，水资源不足的主要原因就是气温升高，即更加温暖的气候，故C项正确。
4．What can be a suitable title for the text?
A．California's Forests：Where Have All the Big Trees Gone? B．Cutting of Big Trees to Be Prohibited in California Soon C．Why Are the Big Trees Important to California Forests? D．Patrick McIntyre：Grow More Big Trees in California
答案：A 标题判断题。本文是一篇调查报告，第一段就点出主题：California has lost half its big trees since the 1930s。后面具体分析了加利福尼亚州大树的现状、造成大树减少的原因等，故A项作为标题最合适。
In the atmosphere, carbon dioxide allows the sun's rays to enter but prevents
the heat from escaping. According to a weather expert's prediction, the atmosphere will be warmer in the year 2050 than it is today, if man continues to burn fuel at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several meters and severely flooding coastal cities. Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere.
In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming, in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels. Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.
However, most of the fuel is burnt in the northern part of the earth, where temperatures seem to be falling. Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has the most effect on the weather?
One possibility is the behavior of the sun. Astronomers at one research station have studied the “hot” spots and “cold” spots, that is, the relatively less hot spots, on the sun. This seems to have a greater effect on the distribution of the earth's atmospheric pressure, and consequently on wind circulation (循环). The sun is also variable (可变的) over a long term. Its heat output (输出) goes up and down in cycles. The latest trend being downward is on the way. But that is only an imagination.
篇章导读：本文是一篇说明文。文章主要介绍了影响气候变暖的诸多原因，包括人类活动和太阳运动。
5．The carbon dioxide in the atmosphere would ________. A．prevent the sun's rays from reaching the earth's surface B．mean a warming up in the Arctic
C．account for great changes in the climate D．raise the temperature of the earth's surface
答案：D 细节理解题。文章第一段讲到二氧化碳在大气中吸收太阳的光线并阻挡热量的流失，文章第二段最后一句话又再次提到二氧化碳能使地球变热的理论。因此，答案为D项。
6．Although the fuel is greater in the northern part, temperatures there seem to be falling. This is ________.
A．mainly because the carbon dioxide is rising
B．possibly because the ice caps in the poles are melting C．due to the effect of the earth's climate D．possibly due to the activity of the sun
答案：D 细节理解题。文章第三段提及这一现象时讲到，科学家们认为：这一现象的产生是因为到目前为止自然界对天气的影响要大于人类对天气的影响。而究竟是哪种自然力量对天气的影响最大呢？文章第四段第一句话给出了答案：其中一个可能就是太阳的活动。D项与此意相符。
7．What does the underlined word “exceeded” mean? A．To be the same as. C．To be better than.
B．To be slower than. D．To be bigger than.
答案：D 词义猜测题。由画线词所在句子中的“natural influences”和下一句中的“which natural cause has the most effect”及最后一段的第三句可知，自然界对天气的影响要大于人类对天气的影响。故选D项。
8．The article was written to explain ________. A．the greenhouse effects B．the solar effects on the earth C．the solar weather
D．the causes affecting weather
答案：D 主旨大意题。全文讲述的是影响天气的诸多原因。只有D项符合题意。 Ⅱ.七选五
(2017·全国卷Ⅱ)Interruptions are one of the worst things to deal with while you're trying to get work done. __1__， there are several ways to handle things. Let's take a look at them now.
__2__. Tell the person you're sorry and explain that you have a million things to do and then ask if the two of you can talk at a different time.
When people try to interrupt you, have set hours planned and let them know to come back during that time or that you'll find them then. __3__. It can help to eliminate (消除) future interruptions.
When you need to talk to someone, don't do it in your own office. __4__， it's much easier to excuse yourself to get back to your work than if you try to get someone out of your space even after explaining how busy you are.
If you have a door to your office, make good use of it. __5__. If someone knocks and it's not an important matter, excuse yourself and let the person know you're busy so they can get the hint (暗示) that when the door is closed, you're not to be disturbed.
A．If you're busy, don't feel bad about saying no B．When you want to avoid interruptions at work C．Set boundaries for yourself as far as your time goes D．If you're in the other person's office or in a public area E．It's important that you let them know when you'll be available F．It might seem unkind to cut people short when they interrupt you G．Leave it open when you're available to talk and close it when you're not 篇章导读：本文是一篇说明文。文章主要就如何避免工作时受到打扰提出了几点建议。 1．B 结合空格后“有几种方法来处理这些情况”，可知B项“当你想在工作中避免受到打扰时”与上下文衔接紧密，故为答案。
2．A 设空处位于段首，根据后文提到的告诉对方你很抱歉，向对方解释你有很多事情要做以及另约时间可知，本段是讲述在自己很忙的时候不要不好意思拒绝，故选A项。
3．E 结合空格前“当人们试图打扰你时，你要确定好时间，让他们知道什么时候回来找你或者你去找他们”，以及空格后“这样做能帮你消除未来受到打扰的可能”，可知E项“让他们知道你什么时候有空非常重要”与上下文衔接紧密，故为答案。
4．D 空格前的“in your own office”与D项中的“in the other person's office”相对应。D项“如果你在别人的办公室或者公共区域”与空格后的内容衔接紧密，故为答案。
5．G 根据空格前的“如果你的办公室有门，那么就好好利用它”可知，本段主要讲述如何利用办公室的门来避免受到打扰。故选G项。
Ⅲ.语法填空
Cultural relics are a part of history, and represent people's cultural treasures. Therefore, it is important for us to protect __1__ (they)．
__2__ we know, most cultural relics are really valuable because they have seen __3__ history of our country, __4__ allow us to have a better understanding of our country's history and culture. We can also learn a lot from our ancestors (祖先) and feel proud of being a Chinese person while __5__ (enjoy) these valuable treasures. In addition, we are able to develop tourism and promote the economy when the well __6__ (protect) cultural relics are open to public.
However, some cultural relics __7__ (damage) by people now. For example, buildings carved (雕刻) __8__ people's names can be seen here and there. There is no doubt that more valuable historical relics will disappear if people keep destroying
(全国统考)2024高考英语一轮复习第1编话题八Book6Unit4Globalwarming课时作业(含解析)
