1 . Small-scale fisheries supply many people with food. Almost all of those in this trade rely on gillnets (刺网) to trap fish. But gillnets trap other things, for example, endangered animals such as turtles; dangerous ones, such as Humboldt squid; and ones that are both endangered and dangerous, such as several types of sharks. Everyone involved would be better off if this did not happen.

Building on studies done both by himself and by others, to try to avoid the accidental netting of turtles, Jesse Senko, a marine-conservation biologist at Arizona State University, has been investigating the idea of fitting LEDs to nets to avoid netting other unwanted by-catch (误捕的鱼) without discouraging target animals. And, as he reports in Current Biology, it seems to work.

Dr. Senko and his team set up an experiment in the Gulf of Ulloa, in Mexico, in which they cooperated with local fishermen to employ over 10,000 meters of nets that had had nets battery-powered waterproof green LEDs fixed onto them every ten meters. Half of these lights were lit. The other half were left unlit, as controls. Each lit net was paired with an unlit one, and the two were used alongside one another at major fishing locations. The fishers’ target fish were large groupers (石斑鱼). Dr. Senko was interested both in what else got caught and whether the lights decreased catches of the target species.

On the latter point, to his relief, they did not. On the former, the lit net s caught 95% fewer kilograms of shark-related species. In particular, several threatened species turned up less often in the lit than the unlit nets.

The advantage from the point of view of fishermen was that they needed to spend a lot less time clearing these dangerous by-catches from their nets. And, crucially, the LEDs concerned are cheap, hard-wearing, and easy to fix. There are also plans to make them solar powered, for easy recharging. Here, then, is an environmental-protection idea from which everyone wins.

Earth Day was founded in 1970 as a day of education about environmental problems, and Earth Day 2020     1     (fall) on Wednesday, April 22 — the holiday’s 50th anniversary. The holiday is now a global celebration that’s sometimes extended into Earth Week, a full seven days of events focused on green living.

    2    (elect) to the U. S. Senate (参议院) in 1962, Senator Gaylord Nelson was determined to convince the federal government that the planet was     3     risk. In 1969, Nelson developed the idea for Earth Day after     4     (inspire) by some teaching activities     5     were taking place on college campuses around the United States.

Denis Hayes, a young activist who had served as student president at Stanford University,     6    (select) as Earth Day’s national coordinator (协调者), and he worked with     7     army of student volunteers and several staff members from Nelson’s Senate office     8    (organize) the project.

The first Earth Day was effective at raising     9     (aware) about environmental problems and transforming public attitudes. Earth Day kicked off the “Environmental decade with a bang,” as Senator Nelson later put it. The theme of Earth Day 2020 is “climate action.” EarthDay.org hopes it will be the     10     (large) volunteer event in history.

7 . Life today is much easier than it was hundreds of years ago, but has brought new peoplems. One of the biggest is pollution. Pollution come in many ways. We see it, smell it, drink it and even hear it.

Men have been polluting the earth. Many years ago, the pollution was not so serious because there were not so many people. When the land was used up or the river was dirty in one place, men moved to another place.

Air pollution is now the most serious. Air makes people sick. And lots of people now are trying to use something to clear the air. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us become angry more easily.

Many countries are making rules to fight air pollution. They stop people from burning coal in houses and factories in the city, and from putting dirty smoke into the air.

Pollution by SO² is now the most dangerous kind of air pollution. It is caused by heavy traffic. It is true that if there are fewer people driving, there will be less air pollution.

Although most of the pollution is caused by us, we are the ones who can change the situation. The earth is our home. We must take care of it. And we must pay more attention to the information in pollution at the same time.

Tibetan antelopes live on the plains of Tibet, Xinjiang and Qinghai. When I     1     (watch) them move slowly across the green grass, I am struck by their     2     (beautiful). At the same time, I am also reminded     3     the danger they are in. Right now they     4     (hunt), illegally, for their valuable fur.

Zhaxi who works at the Nature Reserve (保护区) says, “    5     (actual), we are trying to save ourselves, not only the animals.” In the 1980-1990, the number of the antelopes     6     (reduce) by 50 percent. The hunters were shooting antelopes     7     (make) profits. Their habitats were becoming     8     (small) than before,     9     new roads and railways were built.

In order to save them, the government take     10     (effect) measures and the antelope population has recovered. In June, 2015, the Tibetan antelopes was removed from the endangered list.

9 . One million species face extinction, more than ever before in human history, according to a UN report released in May. And humans should be responsible.

The researchers based the assessment (评估) on some 15,000 sources considering the causes and results of environmental changes over the past 50 years.

The findings are clear and alarming. The researchers have found that about 25 percent of the world’s plants and animals are at risk of extinction. These include sea and land animals. Even the domesticated (驯养的) animals are at risk: Over 9 percent of the domesticated animal species used for food and agriculture might have been lost.

There are some big problems. This rapid decrease of the natural world endangers global food safety and quality of life. For example, about 4 billion people rely on natural medicines, produced by the disappearing species, for their health care.

The researchers identified five drivers responsible for the bad news. They think at the top of the list is the change of land and sea use. The change in ecosystems towards agriculture, aquaculture and other human developments has led to changes in the natural living space of species. It is followed by the direct overuse of creatures (harvesting crops, cutting down the trees, hunting and fishing) and climate change, including rising sea levels and increasing extreme-weather events, wildfires, floods and droughts. The final causes of species extinction are pollution, especially plastics, and the spread of non-native species that can kill native plants and animals. In fact, good ecosystems can promote the growth of species.

The researchers say it is time for humans to act. They think maybe a new global way to save food and refuse waste in our life can turn the tables. Whether that is possible is an open question.