发布时间 : 星期三 文章【单元测试卷】新外研 必修一 Unit 6 单元检测卷(含答案)更新完毕开始阅读b61896ed930ef12d2af90242a8956bec0975a5ff
A. Being thankful is really important. B. Teaching can be very challenging.
C. Teachers should make their students feel loved. D. Developing students’ confidence requires patience.
B
China and India are leaders in improving global（全球的）tree cover, a new study based on NASA research showed.
They took a 31.8 percent part together of the total global new leaf area between 2000 and 2017. China played a major role, adding 25 percent to this increase, and India added 6.8 percent, followed by Canada and Russia.
The study in the Nature Sustainability journal shows that more than 5.5 million square km of green leaf area was added globally. Since 2000, therehas been a five-percent increase in global green cover, it said.
“The greening over the last twenty years shows an increase in leaf areaon plants and trees which is as large as the area of the entire Amazonrainforest,” Chi Chen, a Boston University researcher and lead of the studytold Nature Sustainability. Large plantation activities to protect forests inChina contributed nearly 42 percent to the country’s green cover, andagriculture（农业）added another 32 percent. In India, 82 percent of theincrease in leaf area was because of agriculture.
“China and India take up one-third of the greening, but hold only ninepercent of the planet’s land area covered in green plants,” Chi Chen toldNASA Earth Observatory. “That is a surprising finding, considering the landdegradation（退化）in countries with large populations.”
Boston University’s research team first detected an increase in global green cover in the 1990s but were unsure about what contributed to the increase. Finally, with the help of NASA’s Terra and Aqua satellitesresearch, they managed to find out the increase in leaf cover from differentareas and places.
4. Which country increased the largest part of the new leaf area? A. India. B. Canada. C. Russia. D. China.
5.For what purpose did the author mention the Amazon rainforest? A.To show how great the achievement was. B.To show the importance of rainforest. C.To explain what difficulties we have now. D.To explain the reason for increasing forests. 6.How did Chi Chen feel about the new finding? A.Worried.
B.Interested.
C.Surprised. D.Disappointed.
7.What does the underlined word “detected” probably mean? A.Imagined. B.Discovered. C.Studied. D.Doubted.
C
5G stands for the fifth generation, meaning the next step in the progressof technology to take the place of the present 4G system. 4G took the place of 3G, which came after 2G, and so on. These systems are wireless（无线的）computer networks.
Earlier “G” systems were to improve mobile communication operations. Each new technology brought major improvements in speed and greatlyincreased the network ability. The new 5G system promises more of thesame. However, technology experts say there is a major way that 5G isdifferent from the earlier networks. It will move well beyond mobile networktechnology to influence more industries than other “G” systems.
Wireless industry groups say 5G will help build future “smart cities” byconnecting sensor（传感器）networks. Such networks will be able to controltraffic and quickly find out streetlight problems. 5G is also expected toconnect self-driving cars. Higher 5G speeds could also allow doctors tocommonly perform long-distance operations. Factories and businesses could use 5G technology to improve the collection of information.
However, there are some safety concerns with 5G. More data（数据）— and many more kinds of data — will be traveling across 5G networks. Much of the data could include private information about people,
businesses orgovernment organizations. The increased data flow would give Internetattackers（袭击者）a lot more possibilities to steal and misuse data.
In addition, the wider use of a 5G wireless network means anybreakdown of the network would have more serious results. Such difficultiescould influence public safety as well as world business activity. Governmentnetwork failures could create national safety risks. A failure during a doctor’s long-distance operation could lead to the death of a patient. Or a networkbreakdown could cause terrible accidents of self-driving cars.
8.What are the “G” systems? A.They are wireless industries. B.They are wireless computer networks. C.They are improvements in technology. D.They are generations of computer development. 9.How will 5G change people’s life? A.More people will lose their jobs. B.People will cut down the number of cars. C.We can see a doctor without visiting him. D.We can avoid any serious traffic accidents.
10.What problem may 5G bring to us according to the last two paragraphs?