The Sixth Extinction (灭绝)
Extinctions, where entire species are wiped out, are not unusual in our Earth’s history. In fact, over 90 percent of all species that ever lived are now extinct. In the last 500 million years, there have been five times when life on Earth has almost ended. These include the third mass extinction, known as the “Great Dying”, which killed 90% to 96% of all species. And the fifth event, which occurred 66 million years ago, caused the death of the dinosaurs. The reasons for extinctions are varied. According to scientists, they include volcanic eruptions, asteroids (小行星) hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming. Many scientists say we are now entering the Earth’s sixth mass extinction. This time, human activity will be to blame.
Although it is not unusual for species to die out naturally, the rate at which this is now happening is cause for concern. A 2015 study by scientists who were based at Brown University and Duke University in the US, looked at how quickly species die out due to natural causes, that is, the “background extinction rate”. They found that human activity is causing species to die out 1, 000 times faster than normal. There is a long list of reasons why so many species are dying out: air and water pollution, forests being destroyed, factory farming and overfishing. It is clear that human activity has negatively affected all other species on Earth, including animals and plants.
If a sixth mass extinction occurs, scientists who have studied the issue believe that up to three quarters of all species on Earth could die out. Of course, as we humans depend on so many species for our survival, we would also be at risk of dying out. Our world and our lives depend on the balance in nature between animals and plants. Without forests, we would have no air to breathe and without clean water we would be unable to survive.
Can a sixth extinction be avoided? Experts say that it is not yet too late, if we take action now. If we want to survive, we need to stop destroying the planet that we live on and start to protect it.
1. What are the reasons for extinction in the history?2. Why does the writer believe we will probably die out if 3/4 of the Earth’s species die out?
3. Please decide which part is false in the following statement, then underline it and explain why.
It is not unusual for species to die out naturally, so we human beings are not to blame.
4. What actions can we take to avoid the sixth extinction? (In about 40 words)
2 . Something has changed at a workplace cafeteria in Birmingham. Next to the sandwiches and hot and cold dishes is a small globe symbol, coloured green, orange or red with a letter in the centre from A to E. “Meet our new eco-labels” a sign reads.
Researchers at Oxford University have analysed the ingredients in every food item on the menu and given the dishes an environmental impact score, vegetable soup (an A) to the lemon, spring onion, cheese and tuna bagel(an E). They team up with the food services business Compass Group for a trial at more than a dozen of its cafeterias across the UK to see if a label can change the way people eat.
The challenge for the scientists designing the trial is the image the diners see on the signs. How much information do you include in a label? How do you strike a balance between effective and practical?
During the pandemic, researchers ran studies on an online supermarket where people were given fake money to complete their fake shopping list. The trial gave a sense of what labels were more likely to sway people to buy eco-friendly. They round the most effective way to get people not to buy an item was to use a dark red globe symbol with the word "worse" printed on it. But while effective, it had real world limitations. "You're not going to be able to get anyone to use that unless you threaten them with legislation, because they don't want to say 'don't buy this',"said Brian Cook, the leader of the research.
The next challenge is the scale, especially in supermarkets. Going through tens of thousands of products and countless ingredients, determining the environmental impact in a supermarket would be a Herculean(艰巨的) task. To make it easier, the research team finally decided on four indicators for the trial's formula: greenhouse gas emissions, biodiversity loss, water pollution, and water use. They weighted each indicator equally in their equation for overall impact.
In most cases, the researchers say the biggest environmental impact will be to get people off meat. "Given that the goal is to get people to shift behaviour the most correct and scientifically reliable approach may actually not be the best approach." Clark said. He has considered that a national rollout of labels might need to be based on indicators already prioritised by businesses and mandated (强制执) by governments, to make the move as easy as possible.
1. What has changed at a workplace cafeteria i Burmingham?| A．Food is marked from A to E according to its nutrition. |
| B．Dishes are displayed with an environmental impact score. |
| C．The ingredients in every food item are regularly analysed. |
| D．The restaurant reopened with a sign "Meet our new eco-labels". |
| A．The image does not affect consumers’ opinion |
| B．The dark red globe symbol is a threat to the law. |
| C．An effective image might not be a practical one. |
| D．The image must carry as much information as possible |
| A．damage the interest of the business in food industry |
| B．put more weight on the indicator of greenhouse gas emissions |
| C．combine the benefit for business and the order of the government |
| D．consider whether the approach is supported by scientific evidences |
| A．Eco-friendly, Start from Food |
| B．Off Meat, We Will Be Healthy |
| C．Eco-labels, A New Way We Eat |
| D．Globe Symbol, A New Trend for Business |
3 . Stefani Shamrowicz lives in Colorado. The 24-year-old woman has spent 23 days picking up126 bags of rubbish across the country
Having over a month off from her job at a campus recreation center, Stefani Shamrowicz decided to take a trip to help clean up the environment.
She's now driven over 70 hours through Colorado, New Mexico, Arizona, Texas, Louisiana Florida,Georgia,Tennessee,Kentucky，Ohio，Pennsylvania，and New York-cleaning up everything from pee-filled bottles to lawn ornaments. About 80 percent of the rubbish was drinking bottles. Stefani said she had found a few fast-food toys and a tire with a pair of cowboy boots in it and her aim wasn't to shame, but rather encourage people to do what they can
Collecting anywhere from one to 16 bags at a time, Stefani's been discouraged. She felt she wasn't doing enough. She said there was a place that had an ocean of rubbish and she pushed out four bags, but then she broke down because she realized how much rubbish there was and it felt like four bags didn't do anything. But she remembered to just do what she could, especially since she had gone beyond her goal. She said she dedicated that to her parents because they raised her to be an independent person and had been very supportive on the trip
People donated $10 a bag for Stefani to clean up in their name, which she uses for lodging and gas. The person's name is written on how many bags they've donated towards and Stefani posted a picture on her Instagram when they were filed, thanking them for helping clean up the cit she was in.
People online and in person have responded positively to the project. Stefani recalled people sent her pictures of bags of trash they picked up. Once, when she started doing a bag on the beach in Florida,two ladies saw her and started helping her fill the bag.
With her job resuming June 1, Stefani is now back home but she has so many good things to say about her unique U.S.road trip.There's litter everywhere, so I'm just happy to be able to make a little bit of an impact everywhere I go. Cleaning up this litter is a huge thank you for all the joy and good times national parks and nature in general has brought to my life,”she said.
1. Why did Stefani drive ower70 hours across the USA?| A．To call on people to donate money |
| B．To earn a living by classifying rubbish. |
| C．To encourage people to protect the environment. |
| D．To enjoy the scenery of the national parks and nature |
| A．People offered their help along her journey |
| B．Her parents make joint efforts to support her. |
| C．People begin to donate their money for her project. |
| D．Many people take action to clean up the environment |
| A．Discouraged. | B．Anxious | C．Surprised. | D．Pleased. |
| A．Cleaning up rubbish is a tough task. | B．A kind act can make a big difference |
| C．Believing in oneself is the key to success. | D．One will realize his dream if he persists in it. |
4 . Early fifth-century philosopher St．Augustine famously wrote that he knew what time was unless someone asked him．Albert Einstein added another wrinkle when he theorized that time varies depending on where you measure it．Today's state-of-the-art atomic（原子的） clocks have proven Einstein right．Even advanced physics can't decisively tell us what time is, because the answer depends on the question you're asking．
Forget about time as an absolute．What if，instead of considering time in terms of astronomy,we related time to ecology？What if we allowed environmental conditions to set the tempo（节奏） of human life？We're increasingly aware of the fact that we can't control Earth systems with engineering alone，and realizing that we need to moderate（调节）our actions if we hope to live in balance．What if our definition of time reflected that？
Recently，I conceptualized a new approach to timekeeping that's connected to circumstances on our planet，conditions that might change as a result of global warming．We're now building a clock at the Anchorage Museum that reflects the total flow of several major Alaskan rivers，which are sensitive to local and global environmental changes．We've programmed it to match an atomic clock if the waterways continue to flow at their present rate．If the rivers run faster in the future on average，the clock will get ahead of standard time．If they run slower，you'll see the opposite effect．
The clock registers both short-term irregularities and long-term trends in river dynamics．It's a sort of observatory that reveals how the rivers are behaving from their own temporal frame（时间框架），and allows us to witness those changes on our smartwatches or phones．Anyone who opts to go on Alaska Mean River Time will live in harmony with the planet．Anyone who considers river time in relation to atomic time will encounter a major imbalance and may be motivated to counteract it by consuming less fuel or supporting greener policies．
Even if this method of timekeeping is novel in its particulars，early agricultural societies also connected time to natural phenomena．In pre-Classical Greece，for instance，people“corrected”official calendars by shifting dates forward or backward to reflect the change of season．Temporal connection to the environment was vital to their survival．Likewise，river time and other timekeeping systems we're developing may encourage environmental awareness．
When St．Augustine admitted his inability to define time， he highlighted one of time 's most noticeable qualities：Time becomes meaningful only in a defined context．Any timekeeping system is valid，and each is as praiseworthy as its purpose．
1. What is the main idea of Paragraph 1？| A．Timekeeping is increasingly related to nature． |
| B．Everyone can define time on their own terms． |
| C．The qualities of time vary with how you measure it． |
| D．Time is a major concern of philosophers and scientists． |
| A．present an assumption | B．evaluate an argument |
| C．highlight an experiment | D．introduce an approach |
| A．Those who do not go on river time will live an imbalanced life． |
| B．New ways of measuring time can help to control Earth systems． |
| C．Atomic time will get ahead of river time if the rivers run slower． |
| D．Modern technology may help to shape the rivers’ temporal frame． |
| A．It is crucial to improve the definition of time． |
| B．A fixed frame will make time meaningless． |
| C．We should live in harmony with nature． |
| D．History is a mirror reflecting reality． |
Your Food Choices Affect the Earth’s Climate
Every action has a cost, even for growing food and delivering it to your dinner plate. A team of researchers has found that meat production releases more climate-warming pollution than it does when producing fruits, vegetables, nuts and grains. Their calculations suggest that people could do a lot to slow global warming if they limited how much meat they eat.
There are plenty of “costs” of food. As to the visible costs, people pay money for the food as well as the fuel needed to get groceries to the store or restaurant. However, producing foods also takes resources，for example，the water used to irritate (灌溉）crop fields or the fertilizer and chemicals used to promote plant growth and fight pests.
Peter Scarborough at the University of Oxford in England decided to calculate some of the less-visible pollution created by food production. His team focused on greenhouse gases emitted through the production of our food, including carbon dioxide(CO2)，methane(甲烷） and the nitrous oxide. All three gases are important. While CO2 is the greenhouse gas released in the highest volume, methane and nitrous oxide stay in the atmosphere far longer than CO2 does. As such, they are more powerful in warm the earth’s atmosphere.
They used a computer to change the methane and nitrous-oxide emissions for each person’s diet into its carbon dioxide “equivalent.”That’s the amount of CO2 needed to warm Earth’s atmosphere by the same amount as the methane or nitrous oxide would.
As for the calculations of the carbon dioxide “equivalent(等量)”, in the 1990s, a survey asked65,000 adults what they typically had eaten throughout the past year. Scarborough’s team fed those data into a computer and then included the amount of green house gases linked with producing nearly100 common foods. Then the computer matched those green house-gas amounts to the mix of foods each person had reported eating.
It shows that the diet of someone whose meals included an average of 50 to 99 grams of meat each day would be responsible for the daily release of 5.6 kilograms of CO2 equivalent while those vegans had the lowest diet-linked greenhouse-gas emissions (2.9 kg of CO2 equivalent).
Its authors conclude that reducing the intake of meat and other animal-based products can make a valuable contribution to climate change reduction. And compared to meat, more plant-based food calories can be grown on more lands with less water and other resources. In places where many people are going hungry, raising meat may make it harder to ensure that everyone gets enough to eat.
1. What are the visible costs of food mentioned in the article?2. According to the author, why can our food choices affect the earth’s climate?
3. Please underline the inappropriate part in the following statement and explain why.
Plant-based food can adapt to more types of lands than meat, but they may have a higher requirement of water and other resources, which can be a disadvantage of such food.
4. Apart from food choices, are there any other ways for you to protect the environment? List two or more.
6 . Is Your Diet Destroying the Environment?
A vegetarian diet is often praised for its health benefits. Studies have shown that vegetarians usually have lower levels of heart disease and a lower risk of diabetes than people who eat meat. What most people are less aware of, however, are the effects that a vegetarian diet can have on the environment.
Researchers from the Union of Concerned Scientists in the US recently studied how consumer behavior affects the environment. The study showed that meat consumption is one of the main ways that humans can damage the environment, second only to the use of motor vehicle.
Then, how can eating meat have a negative effect on the environment? For a start, all farm animals such as cows, pigs, and sheep give off methane (沼气) gas by expelling (排出) wind from their bodies. One cow can produce up to 60 liters of methane each day. Methane gas is the second most common greenhouse gas after carbon dioxide. Many environmental experts now believe that it is more responsible for global warming than carbon dioxide. It is estimated that 25% of all methane released into the atmosphere comes from farm animals.
Another way that meat production affects the environment is through the use of water and land. 2,500 gallons of water are needed to produce one pound of beef, whereas 20 gallons of water are needed to produce one pound of wheat. One acre of farmland used for crop production can produce 40,000 pounds of potatoes, 30,000 pounds of carrots, or 50,000 pounds of tomatoes.
Many people now see the benefits of switching to a vegetarian diet, not just for health reasons, but also because it plays a vital role in protecting the environment. However, some nutritionists advise against switching to a totally strict vegetarian, or vegan diet. They believe a vegan diet, which excludes all products from animal sources, such as cheese, eggs, and milk, can be short of many necessary vitamins and minerals our bodies need.
Today, many people know it’s important to take better care of their bodies and to use the earth’s resources more efficiently. As this understanding spreads, more people may realize that to help the environment and for the human race to survive, more of us will need to become vegetarians.
1. The underlined word “it” in Para.3 refers to ___________.| A．methane gas | B．carbon dioxide |
| C．expelling wind | D．greenhouse gas |
| A．growing tomatoes has the highest production |
| B．crop production is better than meat production |
| C．meat production consumes too much water and land |
| D．farm animals are the main producer of the methane gas |
| A．Our diet is destroying the surroundings. |
| B．Raising farm animals affects the environment. |
| C．A vegetarian diet helps to protect the environment. |
| D．More and more people are becoming strict vegetarians. |
Billions of poor people around the world
