Unit 5 Section Ⅰ Starting out & Understanding ideas(Word练习)-【精讲精练】2024-2025学年高中英语选择性必修第一册（外研版）

Ⅰ.阅读理解 A Hundreds of native North American plants，often dismissed as weeds，deserve a lot more respect，according to a new study.These plants，distant cousins of foods like sunflowers and lettuce(莴苣)，actually represent a botanical treasure now facing increased threats from climate change and habitat loss.The crops that the human race now depends on，including grains like wheat and tree fruit like peaches，originally were selected or bred(培育) from plants that grew wild hundreds or thousands of years ago.In the U．S.，there are wild ancestors of blueberries，sweet potatoes，onions，potatoes，and many other food crops.“Some of them are quite common，” says Colin Khoury，a research scientist at the International Center for Tropical Agriculture.“Wild lettuce plants grow along sidewalks，or in backyards，but go unrecognized.” Other crop relatives are rare and threatened.One of Khoury's favorites is the paradoxical sun flower.“It grows just in wetlands of the deserts of New Mexico and Texas.Little salty areas where there's a little bit of water beneath the soil，” he says.So plant growers crossbred it with commercial sunflowers and created new varieties that can grow in places where the soil contains more salt.Other wild relatives may be hiding similarly remarkable gifts，Khoury says，such as genes that could help their domesticated relatives survive diseases，or deal with pests. Khoury and some of his colleagues just finished a survey of about 600 wild crop relatives that grow in North America，and they found that most of these plants are threatened by things like fires，farming and development.The scientists argue that they deserve more protection.For one thing，“gene banks” should collect and preserve them.In addition，these plants need more protection in their natural habitat. According to Khoury，that doesn't necessarily mean setting aside land for them.In many cases，the plants already are growing on public land that's managed by the U．S.Forest Service (USFS) or the Bureau of Land Management(BLM)．“It's more about just being aware that these plants actually exist，” he says. [语篇解读]　本文是一篇说明文。我们现在所食用的多种植物都是从远古时期就存在的野生植物嫁接或育种而来。然而，这些植物的“野生远亲”现在却被人们弃之如草芥，没有得到应有的保护和尊重。研究人员认为，这些野生植物在帮助我们现存的植物应对气候变化、病虫害及栖息地丧失方面可以发挥巨大的作用，我们应该对其加大保护力度。 1．What did the new study mainly focus on? A．Endangered plant species. B．Wild relatives of food crops. C．The impacts of climate change. D．The threats from plant habitat loss. 解析：选B　推理判断题。根据第一段的“Hundreds of native North American plants，often dismissed as weeds，deserve a lot more respect，according to a new study.These plants，distant cousins of foods like sunflowers and lettuce，actually represent a botanical treasure now facing increased threats from climate change and habitat loss.”可知，这项新研究主要关注的是粮食作物的野生亲缘。 2．What do we know about the paradoxical sunflower? A．It needs much water to grow well. B．It grows along sidewalks or in backyards. C．It seems capable of surviving various diseases. D．It helps commercial sunflowers adapt to salty soil. 解析：选D　细节理解题。根据第二段中的“So plant growers crossbred it with commercial sunflowers and created new varieties that can grow in places where the soil contains more salt.”可知，“the paradoxical sunflower”与商用向日葵杂交产生的向日葵可适应含盐高的土壤。 3．How might the scientists feel about their survey results? A．Relieved.　　　　　 B．Concerned. C．Annoyed. D．Critical. 解析：选B　推理判断题。根据第三段中的“Khoury and some of his colleagues just finished a survey of about 600 wild crop relatives that grow in North America，and they found that most of these plants are threatened by things like fires，farming and development.”可知，科学家们对约600种野生植物进行了调研后发现，其中绝大多数的生存状况不容乐观，受到了诸如火灾、农耕及社会发展的威胁。由此可推知，科学家们对其发现会感到担忧。 4．What might Khoury suggest the BLM do? A．Join hands with the USFS. B．Set aside land for wild plants. C．Collect genes of threatened crop species. D．Learn about plants on its managed land. 解析：选D　推理判断题。根据最后一段的“In many cases，the plants already are growing on public land that's managed by the U．S.Forest Service(USFS) or the Bureau of Land Management(BLM)．”和“It's more about just being aware that these plants actually exist”可推知，Khoury可能会建议美国内政部土地管理局去了解其管辖范围内的植物，从而保护这些野生植物。 B In general，the riches of the natural world aren't spread evenly across the globe.Places like the tropical(热带的) Andes in South America are simply packed with unique species，many of which can't be found in any other places.Until recently，the main explanation for the biological riches concentrated in places like the Amazon Basin was that such places must be engines of biodiversity (生物多样性)，with new species evolving at a faster rate than other parts of the world.But now，new research on bird evolution may turn that assumption on its head，instead supporting the idea that areas with fewer species actually tend to produce new species faster. The researchers say these biodiversity “coldspots” are generally found in environments featuring freezing，dry and unstable conditions.Though the researchers found these locations with few bird species tend to produce new ones at high rates，they fail to accumulate many species because the unstable conditions frequently make the new life forms die out. The more well­known“hotspots”，by contrast，have accumulated their large numbers of species by being warm，hospitable and relatively stable.Indeed，the researchers found that the countless bird species that call the Amazon home tend to be older in evolutionary terms.“New species do form in places like the Amazon，just not as frequently as in the dry grasslands in the Andes，” says Elizabeth，an evolutionary biologist at the University of Tennessee. The researchers managed to collect 1,940 samples representing 1,287 of the 1,306 bird species from South America.Their analysis showed that the best predictor of whether an area would produce new species at a high rate was how many species lived there，rather than climate or geographic features like mountains.Species­rich areas tended to produce new species more slowly. “Maybe had environments generate new species more frequently because there's less competition and more available opportunities for new species，” says Gustavo Bravo，a lead researcher. The study's findings add new urgency to protect ecosystems that may look barren, but may actually be nature's hothouses for the evolution of new species. [语篇解读]　本文是一篇说明文。一项新的研究发现，物种较少的地方比物种丰富的地方会更快地产生新物种。 5．Why is South America mentioned in the first paragraph? A．To make comparison. B．To introduce the topic. C．To make a prediction. D．To draw a conclusion. 解析：选B　推理判断题。文章第一段提到像南美洲热带安第斯山脉这样的地方有大量独特的物种，然后介绍了直到最近关于生物多样性集中到某些地方的主要解释；接着在第一段最后一句点明新研究可能会颠覆这一假设，反而支持物种较少的地区实际上更快产生新物种的观点。由此可推知，文章提到南美洲是为了引出新的研究发现，即引出话题。 6．What determines the rising rate of new species in a place? A．The number of its species there. B．The environment there. C．The survival skills of species. D．The different biological factors. 解析：选A　细节理解题。根据第四段内容可知，他们的分析表明，预测一个地区是否会以高速率产生新物种的最佳指标是有多少物种生活在那里，而不是气候或山地这样的地理特征。 7．Which of the following can best explain the underlined word “barren” in the last paragraph? A．Dry and bare. B．Lively and active. C．Nice and green. D．Complex and unpredictable. 解析：选A　词义猜测题。根据上文内容可知，研究发现，也许恶劣的环境更频繁地产生新物种；再根据画线词所在句的内容可知，需要保护的生态系统可能是新物种进化的自然温室。由此可推知，画线词描述的应该是恶劣的环境。结合选项可知，A项(干燥且光秃秃的) 符合语境。 8．What is the main idea of the text? A．Tropical areas are home to large numbers of species. B．New species prefer to live in the extreme climate. C．Harsh environments pose a greater threat to species. D．The worst ecosystem may give birth to new species fastest. 解析：选D　主旨大意题。文章第一段最后一句表明，有关鸟类进化的新研究可能会推翻以前的假设，反而支持物种较少的地区实际上会更快地产生新物种；接着下文具体介绍了该研究的发现；文章倒数第二段一位研究员的话说明了恶劣的环境更频繁地产生新物种的原因。由此可知，D项(最糟糕的生态系统可能会最快地产生新物种) 是本文的主旨。 Ⅱ.完形填空 I was having a hard time trying to find work.The economy in our area was in pretty 1 shape.And I was 2 for what to do next when I answered the online 3 . NEEDED：someone to cut and split(劈) wood. I drove to the address and there on the front field was a huge 4 Elm tree blown by strong winds.An old lady was sitting 5 at the door.We 6 on $150 to do the job. The old Elm was tougher than I had 7 .My chainsaw (电锯) cut it fine，but when I tried to split it，my chainsaw was 8 .So I had to borrow a wood splitter from her neighbour. I managed to finish the task at dusk.As she looked at the huge pile of wood on the lawn，an 9 expression worked its way across her face.She invited me in for 10 .With tears building up in her eyes，she 11 me a sandwich and said，“I am sorry...the $150 I promised to pay you is going 12 .I had it in my purse but nowhere to be found.That is what 13 money I have saved for half a year.” Seeing her home was not 14 ，I realized she was having a hardship worse than I．I comforted her and then 15 what firewood would fit into her wood storage room. On the way home I thought to myself...“It Is What It Is”． [语篇解读]　本文是一篇记叙文。主要讲述了作者因为找不到工作，只好在网上接些临工广告。作者接到一个被大风吹倒的大树需要伐木的生意，作者伐完木之后，老妇人积攒了半年并答应作者应付的150美元不见了。作者看到老妇人不太体面的家庭，意识到她比自己更困难。 1．A.rough　　　　　　 B．unique C．different D．active 解析：选A　根据“I was having a hard time trying to find work.”可知，作者找工作困难，说明经济状况相当糟糕。 2．A.at a time B．at a loss C．in a way D．in the mood 解析：选B　根据“what to do next”可知，作者在网上接一些活，具体下一步做什么，作者不知所措。 3．A.course B．platform C．advertisement D．activity 解析：选C　根据“NEEDED：someone to cut and split (劈) wood.”可知，作者是在网上接一些临工广告。 4．A.growing B．upstanding C．rotten D．fallen 解析：选D　句意：我开车去了那个地址，前面的空地上有一棵巨大的榆树被强风吹倒了。 根据“Elm tree blown by strong winds.”和常识可知，大树是被强风吹倒的。 5．A.helplessly B．happily C．thoughtfully D．leisurely 解析：选A　根据“NEEDED：someone to cut and split (劈) wood.”可知，老妇人登广告找人伐木，说明她当时是无助的。 6．A.insisted B．agreed C．looked D．depended 解析：选B　根据“I am sorry...the $150 I promised to pay you is going .”可知，老妇人同意花150美元让作者做这项工作。 7．A.anticipated B．mentioned C．remembered D．experienced 解析：选A　根据“So I had to borrow a wood splitter from her neighbour.”可知，作者不得不借劈柴器，说明老榆树比作者预期的要结实。 8．A.unusual B．sharp C．useless D．faultless 解析：选C　句意：我的电锯切得很好，但当我想把它劈开时，我的电锯就没用了。 根据“So I had to borrow a wood splitter from her neighbour.”可知，作者的电锯没有用，所以不得不借劈柴器。 9．A.astonished B．annoyed C．abstract D．anxious 解析：选D　句意：当她看着草坪上那一大堆木头时，一种焦虑的表情掠过她的脸庞。 根据“With tears building up in her eyes，she me a sandwich and said，‘I am sorry...the $150 I promised to pay you is going .I had it in my purse but nowhere to be found.That is what money I have saved for half a year.’”可知，老妇人答应给作者的150美元不见了，所以当时的状态是焦虑的。 10．A.breath B．dinner C．shift D．money 解析：选B　根据“I managed to finish the task at dusk.”可知，作者在黄昏时完成了任务，所以老妇人邀请作者吃晚饭。 11．A.served B．returned C．owed D．bought 解析：选A　句意：她眼里满是泪水，递给我一个三明治，说：“对不起……我答应付给你150美元不见了。我把它放在包里，但哪儿也找不到。这是我半年来存的一点钱。” 根据“She invited me in for .”可知，老妇人用三明治招待作者。 12．A.fast B．short C．missing D．shopping 解析：选C　根据“I had it in my purse but nowhere to be found.”可知，老妇人的150美元不见了。 13．A.extra B．remaining C．much D．little 解析：选D　根据“I have saved for half a year.”可知，150美元是老妇人半年来才存的一点钱。 14．A.attractive B．old­fashioned C．decent D．secure 解析：选C　句意：看到她的家不体面，我意识到她的困难比我更严重。根据“I realized she was having a hardship worse than I．”可知，老妇人的家是不体面的。 15．A.piled B．changed C．backed D．broke 解析：选A　句意：我安慰她，然后把能装下的柴火堆进她的木头储藏室。 根据“what firewood would fit into her wood storage room.”可知，作者帮助老妇人把劈下来的木材堆进她的木头储藏室里。 学科网（北京）股份有限公司 $$