Unit 4 Global warming
Ⅰ.阅读理解
A
They may be tiny, and live for just three months, but ants could be the key to solving climate change.
Rough harvester ants have been found to “weather” minerals in sand to produce calcium carbonate, also known as limestone(石灰岩)．When the ants make this limestone, the process traps carbon dioxide in the rock, ultimately removing it from the atmosphere.
It is uncertain how the minerals are changed, however, and theories vary a lot from ants licking the sand to excreting (排泄) the substance.
Professor Dorn buried sand at six sites in the CatalinaMountains in Arizona, and PoloDuroCanyon in Texas, 25 years ago. Every five years, he measured the minerals in the sand, and discovered the ants broke down minerals up to 300 times faster than sand left undisturbed.
Professor Dorn believes the ants collect calcium and magnesium(镁) and use these elements to make the limestone. This may occur when ants lick sand grains to stick them to the walls of their nests. Alternatively, the limestone could be created from bacteria in the insects gut before it is excreted. This process is similar to what's known as carbon sequestration(隔离)．
Natural carbon sequestration is the process on Earth that manages the carbon dioxide expelled by animals and humans. Trees and the oceans help trap this carbon dioxide.
Another method is geological sequestration where the carbon dioxide is pumped into underground chamber, or into areas full of calcium and magnesium. Carbon dioxide reacts with these elements to form limestone. It is this latter method that Dorn believes the ants perform naturally.
But Professor Dorn claims it is still unknown how much atmospheric carbon is removed by the ants.
语篇导读 本文为说明文。多恩教授认为，蚂蚁也许是应对气候变化的关键因素。他通过实验证明蚂蚁能够吸收空气中的二氧化碳，但是具体能吸收多少至今尚未确定。
1．The fifth paragraph is mainly about ________. A．how ants break down limestone
B．how ants change minerals into limestone
C．how ants decorate their nests with sand D．how ants use sand to kill bacteria
解析 B 主旨大意题。本段大意：多恩教授认为蚂蚁舔沙砾把它们粘在巢穴的墙上时，可能会收集钙和镁制造石灰岩。或者，石灰岩可以从蚂蚁的肠道细菌中产生，再排泄出来。这都是关于蚂蚁如何制造或产生石灰岩的，故选B 项。
2．What is the possible meaning of the underlined word “expelled”？ A．Sent out. C．Broken up.
B．Taken in. D．Given away.
解析 A 词义猜测题。本句句意：地球上自然碳汇是处理动物和人类expelled的二氧化碳的过程。根据常识可知，动物和人类排放二氧化碳。send out放出；take in 吸收；break up打碎，结束；give away泄露(消息、秘密等)，故选A项。
3．According to Dorn, scientists still don't know ________. A．the effect of CO2 on ants' survival B．the method of ants' removing CO2 C．the amount of CO2 removed by ants D．the time when ants absorb CO2
解析 C 细节理解题。根据最后一段可知，多恩教授目前尚不清楚蚂蚁吸收了多少大气中的碳，故选C项。
4．The main idea of the passage is that ________. A．ants build their nests to keep CO2 out
B．ants use limestone to absorb a great deal of CO2 C．ants are pioneers in solving global warming D．ants may remove CO2 from atmosphere
解析 D 主旨大意题。第一段说．..but ants could be the key to solving climate change，后面介绍了多恩教授的实验，最后多恩教授称目前尚不清楚蚂蚁吸收了多少大气中的碳。因此全文主要讲蚂蚁可能会吸收大气中的二氧化碳并介绍相关实验，故选D项。
B
During a research experiment a marine(海洋) biologist placed a shark into a large holding tank and then released several small fish into the tank. 5.________
The marine biologist then inserted a strong piece of clear fiberglass(纤维玻璃) into the tank, creating two separate parts. She then put the shark on one side of the fiberglass and a new set of small fish on the other.
Again, the shark quickly attacked. This time, however, the shark hit the fiberglass divider and bounced off. 6.________ Meanwhile, the small fish swam around
unharmed in the second part. Eventually, about an hour into the experiment, the shark gave up.
This experiment was repeated several dozen times over the next few weeks. 7.________ Eventually the shark got tired of hitting the fiberglass divider and simply stopped attacking altogether.
The marine biologist then removed the fiberglass divider, but the shark didn't attack. 8.________ So, they swam wherever they wished, free from harm.
Like the shark in the story, many of us, after experiencing setbacks and failures, emotionally give up and stop trying. 9.________ In other words, we continue to see a barrier in our heads, even when no “real” barrier exists between where we are and where we want to go.
A．At the same time, the shark tried again and again.
B．We believe that because we were unsuccessful in the past, we will always be unsuccessful.
C．The shark was trained to believe a barrier existed between it and the small fish.
D．It kept repeating this behavior every few minutes fruitlessly. E．We should keep on trying even if we meet obstacles.
F．Each time, the shark got less aggressive and made fewer attempts to attack the small fish.
G．As you would expect, the shark quickly swam around the tank, attacked and ate the smaller fish.
语篇导读 本文为议论文。大鱼吃小鱼是自然法则，也是鲨鱼的生存法则。然而，当鲨鱼与小鱼之间多了一块透明纤维玻璃后，鲨鱼又会做出怎样的举动呢？
5．解析 G 顺承关系。上句讲到：在一项实验中，海洋生物学家将鲨鱼放入一个大型水槽，并在水槽中放入了几条小鱼。承接上句，空处应讲到放进小鱼的后果，即G项：正如你所想的，鲨鱼迅速在水槽中游动，袭击并吃掉小鱼，故选G项。
6．解析 D 顺承关系。本段共分为三个部分，第一部分讲到鲨鱼像上次一样进攻小鱼但被纤维玻璃弹开，第三部分讲到结果是鲨鱼放弃了吃小鱼，因此中间的一部分是承上启下，讲述鲨鱼一遍遍尝试的过程，故A、D两项符合题意，然而A项中的at the same time与下文中的meanwhile重复，故选D项。
7．解析 F 递进关系。上句讲到这项实验在接下来的几个星期里重复了好几十次。下句交代了实验结果：鲨鱼最终疲于撞击纤维玻璃挡板，因此停止了攻击行为。在此之前，实验中所显现的过程如F项：每一次实验，鲨鱼的攻击性越来越弱，袭击小鱼的尝试越来越少，
全国通用版2019版高考英语大一轮复习单元检测卷29Unit4Globalwarming新人教版选修6
