1 . Last week, a team of Harvard researchers announced they were on the brink of creating a hybrid woolly mammoth-elephant embryo, the next step on the long road to resurrecting (使复活) the pre-hsitoric creatures. As we move steadily closer to being able to bring extinct species or something, closely resembling them-to life through genetic engineering, some scientists say the technology could prove a valuable, much-needed conservation tool.
But a new economic analysis suggests that bringing back extinct species may detract from, rather than add to, conservation efforts. “Given this atmosphere of a biodiversity crisis and limited resources, we really need to do the best job we possibly can, ” says Joseph Bennett, a biologist at Carleton University in Ottawa and lead author of the study. “If de-extinction represents a gain in biodiversity, that's great. If it represents a Pvrrhic victory in that we could have better spend those resources to save species on their way to extinction, that's essentially a one step forward, two steps back scenario."
The study, published Monday in the journal Nature Ecology and Evolution, used data from New South Wales, Australia, and New Zealand to consider the cost of sustaining de-extincted populations under two scenarios. In the first scenario, a private agency funds the resurrection of an extinct species, then hands the responsibility of caring for the revived population over to the government. In the second, a private agency pays for the entire project, covering the costs of both resurrection and maintenance.
The results, researchers found, showed no good sign for endangered, living species. Under the first scenario, the cost of maintaining the de-extincted species was taken directly from the governments' already limited conservation budget, resulting in an overall loss for biodiversity: Roughly two species would go extinct for every one resurrected, the team concluded. The second scenario produced a small increase in biodiversity, particularly for species that would require the same conservation tools and techniques already being used to protect endangered animals.
But the greatest hypothetical gains for biodiversity, the study said, came when the money required for de-extinction was instead put toward existing conservation programs for living species. In this scenario, roughly two to eight times more species were saved.
Bennett and his team aren't the first to question whether de-extinction would help or hurt conservation efforts. Other scientists have argued that harnessing the technology to bring back extinct species, or something closely resembling them, could take away momentum from the push to protect endangered animals and give property developers an excuse to build over their natural habitats.
1. As indicated in Paragraph I, it seems that some scientists ________.| A．take a vain pride in their conservation tool. |
| B．think highly of the conservation technology. |
| C．show greater interest in the prehistoric creatures. |
| D．are pessimistic about bringing back extinct species. |
| A．rewarding | B．thankless |
| C．fruitless | D．harmful |
| A．de-extinction may not help conservation efforts. |
| B．the government assumes part of responsibility |
| C．the cost of maintenance outweighs that of revival. |
| D．extinction poses a greater threat to biodiversity. |
| A．sustained biodiversity. | B．endangered animals |
| C．private properties | D．extinct species. |
Karachi,Pakistan,is one of the hottest cities on Earth. In June 2015, more than 1,000 people died there during a heat wave (热浪期). “It was a terrible time,” Shahzad Qureshi said, “we needed
Following that heat wave, Qureshi started a group
Trees help cool the air by providing shade (荫）and giving out moisture (湿气）through
For its first project, Urban Forest planted about 1,300 trees in a park in Karachi. The group uses a special method
Since 2015, Qureshi and his team
In2017, Qureshi helped plant an urban forest at Karachi Grammar School. He met with students to teach them
3 . Dogs are great companions for people. However, there is a wide variety to choose from.
·Be aware of your housemates.
You’ll first want to think about the people and creatures that you live with. If you have a roommate or family member who is allergic to dogs, doesn’t like them, or simply doesn’t want one, this problem will need to be resolved. Similarly, if you have other pets that are not compatible(和谐共存的)with dogs, you will want to reconsider.
·Think about the amount of time you have.
·Consider your lifestyle. You will also need to think about your life and how a dog will fit into it. A large dog will absolutely require walks to keep healthy and mentally alert, especially if you don’t have a large space for them to run around in.
| A．Decide the best size. |
| B．Choose an appropriate age. |
| C．You may find that it is not possible for you to get a dog. |
| D．You will also have better access to the dog’s medical history. |
| E．Different dogs will fit some lifestyles and people better than others. |
| F．Getting a dog that needs lots of exercise when you work a lot is bad. |
| G．Most dogs are very social and require a great deal of attention and love. |
4 . Some Chinese students born in the 1990’s created a microsatellite that took a stunning picture of the moon and the Earth in space, an image praised as one of the best of the two celestial bodies and one that Science magazine also used on Feb.15, 2019.
The photograph was done by the camera on Longjiang 2, a microsatellite developed by students at the Harbin Institute of Technology in Northeast China's Heilongjiang province.
Before its publication in the leading scientific journal, the picture had been widely circulated on mainstream media worldwide, with some foreign media outlets even praising it as one of the best photos of the moon and the earth so far.
Wei Mingchuan, born in 1991, was the chief designer responsible for the sub-system of Longjiang 2, a microsatellite launched last year together with Queqiao, the relay satellite for the Chang'e 4 lunar probe. Wei successfully developed LilacSat 1 -- the country's first microsatellite independently designed, developed and controlled by students -- and has been dubbed China's "youngest chief designer", despite being the oldest in his team.
Tai Mier, one of Wei's team members who was born in 1996, designed the camera on Longjiang 2 that captured the amazing picture of the moon and the Earth. Tai was only 20 years old when work on the project began.
The youngest member in the team is 20-year-old Huang Jiahe, who handled software design for the Longjiang 2 ground station. Beginning in primary school, Huang would buy all kinds of electronic components and parts. At first, he just simply disassembled and assembled the parts, but now he can design and create things. This young man, considered a genius by some, said that he is just curious and passionate about aerospace technology.
In their dormitory, aerospace-related items are everywhere. A postcard on the wall is printed with the words "we were born for our dreams", a reminder that the future has just begun for this youngest team of the Chang'e 4 mission.
1. What does the underlined word “dub” in Paragraph 4 mean?| A．describe | B．nickname |
| C．transform | D．announce |
| A．2019 | B．2018 |
| C．2017 | D．2016 |
| A．The photograph had been known before Science issued it. |
| B．Wei Mingchuan is the youngest chief designer in the team. |
| C．The photo of the moon and the Earth was viewed as the best one. |
| D．Queqiao was launched with the Chang’e 4 lunar probe . |
| A．The best photograph was issued in the latest Science magazine. |
| B．The designers of the Longjiang2 are the youngest team. |
| C．An amazing picture was captured by a microsatellite made by Chinese students. |
| D．Longjiang2 was created by some Chinese students born in the 1990s. |
5 . It’s hard to imagine that just 25 years ago, Berlin was a city split (分开) into two by the Berlin Wall. I’ll never forget how people were excited as the Berlin Wall came down in 1989. Since then, Berlin has become one of the coolest cities in Europe. Here are the main reasons why I think Berlin is cool.
It’s affordable. Berlin has cheap hotels and everyday objects. You don’t have to worry about spending too much money when visiting Berlin.
It has fantastic festivals. Berlin knows how to give parties, and there is a festival here every month of the year. Perhaps the most famous is the Berlin International Film Festival.
It has great architecture (建筑设计). Berlin has beautiful architecture of its own. The Brandenburg Gate, built in the 18th century, is one of the city’ s most famous buildings, symbolizing more than 200 years of history. The TV Tower is as good as the Eiffel Tower in Paris and the London Eye.
The art scene is flourishing (繁荣). Berlin is a city of living art. Artists are allowed to create works of art on the sides of buildings.
If you want to visit an affordable European city with culture and lots of colors, Berlin is the place to be. What are you waiting for? Get to Europe’s coolest city before everyone else discovers it.
1. The underlined word “affordable” in Paragraph 2 means “________” in Chinese.| A．可利用的 | B．可触及的 |
| C．付得起的 | D．用得住的 |
| A．Once a week. | B．Twice a week. |
| C．Once a month. | D．Twice a month. |
| A．Its color. | B．Its history. |
| C．Its location. | D．Its architecture. |
| A．He can’t stand it. | B．He thinks it’s boring. |
| C．He doesn’t mind it. | D．He thinks it’s cool. |
Today, we buy more clothing
Fast fashion clothing is designed to fall apart fast,
Businesses can be environmental-friendly, too. For example, an online clothing store promises
Covering 7 million square kilometers of jungle and river over eight countries, the Amazon Rainforest is home to millions of sorts of plants and animals, some of
The Amazon Basin
With the destruction of the Amazon Rainforest, global warming becomes more of a threat. It is up to each individual to fight against the
8 . The measurable threat to the environment has been worsened by the spread of COVID-19 that increases the need for plastic protective equipment. Most plastic is made from fossil fuels. Millions of tons of greenhouse gas are released from the development of these resources and plastic production and burning.
The end life of plastic is just worrisome. Less than 10% of the plastic produced has been recycled. Even more of it has been burned. But the vast majority of plastic has been buried inland, and it is increasingly polluting the environment. We hear mostly about ocean plastic and the harm done to sea creatures that mistake plastic bags and bits for food. But microplastic is even more worrisome. Plastic doesn't break down biologically but instead breaks down into tiny particles（a very small piece of something）, which have been found in every corner of the planet, on land and in the air, in drinking water and food sources.
Yet the public has not given this global environmental disaster the attention it requires. Instead, they have viewed single-use plastic—which makes up about 40% of plastic used each year—as a litter issue that can be solved through better recycling and waste management. That attitude must change because the recent global breakdown of the market for recycling has made it clear that it has never been, nor ever will be, able to keep up with plastic trash use.
California has been the forerunner of plastic waste reduction—it was the first state to ban single-use plastic bags and may be the first state to transform the way goods are packaged. The state also came close to passing an act which would have required that products sold in plastic packaging in the state have a proven recycling rate of 75% by 2032. California, though influential, can't solve this crisis alone. The US has long been producing a great amount of plastic trash and it should engage in reducing the use of plastic as well.
1. Why does the author mention the release of greenhouse gas in paragraph 1?| A．To show the harm of plastic |
| B．To warn of the climate change. |
| C．To call for the development of fossil fuels. |
| D．To highlight the importance of plastic equipment. |
| A．Favorable. | B．Tolerant. |
| C．Curious. | D．Opposed. |
| A．A pioneer. | B．A failure. |
| C．An objector. | D．A predictor. |
| A．Microplastic Products Are Harmful |
| B．Waste Recycling Is an Urgent Matter |
| C．Plastic Waste Pollution Is a Wake-up Call |
| D．Global Environmental Disasters Are Increasing |
9 . In the United States，many teachers keep fish，hamsters(仓鼠)，and other animals in their classrooms.Teachers say students learn important lessons from the animals.More than 70 percent of teachers who have classroom pets say the animals help students learn responsibility.Research also shows that classroom pets can reduce stress.
“Pets can comfort kids who are having a bad day,”says Lisa Robbins，who works fora group called Pets in the Classroom.
But others think pets should be expelled from classrooms. In January，the Durango School District in Colorado began following a no-pet policy(政策).Now animals can be brought into Durango schools for certain lessons，but they can't stay.Officials were worried that animals might create problems for kids with allergies(过敏症).They were also concerned about the animals getting proper care.
Here's what two of our readers think.
Having classroom pets gives students a fun way to learn about animals. In my class last year，we had a class pet named Elliot.Our teacher also used him to teach us about different subjects.For example，in math，we calculated (计算)how much it costs to feed Elliot for a year.
Pets also help kids learn how to work as a team. My classmates and I took turns feeding Elliot and cleaning his tank,
If teachers are worried about students with allergies，they could get pets that don't have fur.
—D' Lasia Mays，Texas
Classroom pets can take away valuable class time.Some students might have a hard time focusing on the teacher when there are animals in the room.
Plus，having a classroom pet can cause safety problems. You never know how an animal will react to students.Even a cute little hamster might hurt a kid who sticks his or her hand in its cage.
—Patrick McKinney，Ohio
1. What does the underlined word " expelled”in Paragraph 3 probably mean?| A．Allowed. | B．Removed. |
| C．Protected. | D．Educated. |
| A．Classroom pets are not allowed at schools. |
| B．Animals are not allowed at schools. |
| C．Many teachers have pets without fur. |
| D．Many students are allergic to animals. |
| A．He needs special training. | B．He needs more proper care. |
| C．He has educational value for kids. | D．He is not only lovely but very smart. |
| A．The author. | B．Lisa Robbins. |
| C．Patrick McKinney. | D．D' Lasia Mays’ teacher. |
10 . In hot countries the woods are not like our woods. They are great dark forests, where the trees grow so closely together, and are so tall, that if you looked up you could hardly see the sky.
Then there are a great many climbing plants, which twist themselves round and round the trunks and branches of the trees. They are called vegetable cables, because they are so much like ropes. They reach from one tree to another, and almost fill up the spaces between. Troops of monkeys run along the vegetable cables from one tree to another, or swing from the branches by their tails, making a noise all the time as if they are talking to each other. When night comes they roll themselves into a ball, gathered together as close as may be, to keep themselves warm.
Dangers of every kind lie in the forest. The poisonous snake may lie coiled among the bushes, or traces of the wild American tiger may be seen upon the path.
Then there are all sorts of wonderful birds, such as we never see in our country, except in cages. Birds, beasts, and insects live there, for the most part, undisturbed. It is their home; and on every side they are at work, hunting their prey, or escaping from danger. For though man seldom wages war upon them, these wild creatures of the forest are engaged in constant warfare with each other; and the weak are always using some plan to protect themselves from the strong.
There are a great many curious things to be seen in these South American forests.
1. Why are the forests in hot countries so dark?| A．Because it is cloudy and rainy in the woods. |
| B．Because there is no sunshine shinning there. |
| C．Because it is night time there all year around. |
| D．Because the trees are tall and grow closely together. |
| A．Twisting trunks. | B．Vegetable cables. |
| C．Rolling ropes. | D．Grape branches. |
| A．By their talking. | B．By their running. |
| C．By their noises. | D．By their tails. |
| A．rolled | B．injured |
| C．climbed | D．poisoned |
| A．Trees, trunks and branches. | B．Monkeys, snakes and tigers. |
| C．Birds, beasts, and insects. | D．Man, fruits and vegetables. |
