The Amazon rainforest is the largest rainforest in the world, which plays     1    significant role in     2     (keep) the fine balance of the Earth’s ecosystem. It crosses into eight     3     (country) and covers an area of around 6 million square kilometers. The Amazon River, from which the rainforest gets     4     (it) name, supports many different ecosystems on its journey. They give this area the     5     (rich) biodiversity on the Earth. Of the 390,000 plant species known to us, more than 40,000 can     6     (find) in the Amazon. Each level of the forest forms its own little world, home to different kinds of     7     (live) things. More than 1,300 species of birds and over 400 species of mammals hide among the jungle’s plant life,    8     form the forest’s food chain. The Amazon rainforest is often known     9     the “lungs of the planet”. However, over the past 50 years, about 17 percent of the rainforest     10     (disappear) due to human activities. Can we afford to damage the “lungs of the planet”?

Many of us were raised with the saying “waste not, want not”. None of us, however, can     1     (complete) avoid waste in our lives.

Any kind of waste is thoughtless. Whether we waste our potential talents,our own time, our     2     (limit) natural resources, our money     3     other people’s time, each of us should become more aware and careful. The smallest good habits can make a big difference.     4     is a good feeling to know in our hearts that we are doing our best in a world that is in serious trouble. By focusing     5     saving oil, water, paper, food and clothing, we are playing a part in     6     (cut) down on waste. We must keep reminding ourselves that it is     7     (easy) to get into something than it is     8     (get) out of it. Actually, severe damage     9     (do) to our land recenly in the history of our evolution. It’s time for us to say no to waste so that our descendants (后代)     10     (be) able to develop well. We can’t solve all the problems of waste, but we can encourage mindfulness (察觉).

The extinction of the Chinese paddle-fish (白鲟) and wild Yangtze sturgeon (野生长江鲟鱼),     1     (announce) by the international Union for Conservation of Nature (IUCN), started a wave of comments on china’s social media recently, demanding more environmental     2     (protect).

The IUCN’s latest list of threatened species showed that 100% of the world’s remaining 26 sturgeon species are now at risk of extinction, up from 85% in 2009. “The assessment, based on new calculations, shows their decline over the past three generations is     3     (sharp) than previously thought,” the organization said,     4     (add) that the reassessment had also confirmed the extinction of the Chinese paddle-fish. Both the Chinese paddle-fish and the Yangtze sturgeon were common species in the Yangtze river basin,     5     have been troubled by heavy shipping. traffic, overfishing and water pollution.

The Chinese paddle-fish was one of     6     biggest freshwater fish species in the world and could grow up to 7 meters in length. The IUCN ranked it among “    7     (critical) endangered” for the first time in 1996     8     (warn) people of the possibility of its extinction. The Yangtze sturgeon could grow up to 8 meters. Its meat was considered delicious in China.     9     a source of caviar (鱼子酱), it     10     (catch) in great numbers and was purchased at a high price.

Water shortage is knocking at the door. It is one of the     1     (great) crises facing us today, with two thirds of the global population     2     (live) in areas where water is short for a month or more every year. There are two main factors (因素) leading     3     this problem: increasing global demand for water, and unsustainable means by which these demands are being met. Though global water usage     4     (increase) a lot over the last fifty years, it is predicted that there will be a further 60%-100% increase in water usage by 2050.

This is not just     5     matter of turning the tap off when you brush your     6    (tooth), cutting your showers down to 3 minutes, or sharing the washing-load with your roommates. In fact, daily activities of human make up less than 4% of our total water usage, with 92% falling into two groups,     7     are the industrial production of household items and the production of food. Astonishingly, 69% of our total daily water usage comes from the     8     (grow) and production of food alone.

    9     (unfortunate), there is no reference book for the exact number of liters (升) used in the production of any individual food item. This is a hard thing to do, for we have other factors     10     (consider) when weighing up the benefits of every food choice: taste, cost and convenience.

Whales have been facing serious danger for a long time.

First, due     1     the greenhouse effect, glaciers are melting, and some living creatures in the Antarctic and the Arctic are in danger of     2     (extinct). Besides, with global warming     3     (become) worse, life in other parts of the ocean has also been seriously affected, including whales.

Secondly, whaling activity is another killer. Historically, whaling has been popular in some overseas countries, such as England, Japan and Norway. Some people's desire for money can't     4     (meet) easily, and they regard whales as a money-making machine. A kilogram of whale meat can fetch about $100 in Japan. Besides, advanced technology has increased the efficiency of whaling and     5     (great) reduced the number of whales. What's more, some countries are still on whaling in     6     name of science.

The fact     7     whales have become endangered animals is alarming us. Some     8     (organization) have begun working hard to save them. The international community     9     (make) a strategy against commercial whaling. In my opinion, governments should also make laws     10     (protect) whales.

Litter is everywhere, doing great harm     1     the environment and life on our planet. Jeff Kirschner, who wants to build a litter-free world, started a     2     (globe) community named Litterati     3     (settle) this problem.

The story began with his 6-year-old daughter. One day they were going on a hike when the girl noticed a     4     (break) plastic tub in a river. She said, "Daddy, that doesn't go there." That took Kirschner by surprise. He, like many adults, had become so used to the rubbish around them that he hadn't given it a second look.     5     his daughter said reminded him of the serious problem our planet faces.

Jeff started to take action.He created Litterati, an app that makes it fun to pick up litter. The idea is     6     (fair) simple: Spot a piece of trash, take a photo, post the photo online and then put the litter into the dustbin.

    7     (see) Jeff’s positive impact on the planet, people worldwide started participating. Up to now, over 2,500,000 photos posted by 3,500 people from 40 countries     8     (find) their way to Litterati's digital landfill.

Litterati is more than an app. It is a highly     9     (effect) solution to a pressing issue. Wherever you live, whatever you do and     10     you are, join Litterati to make the world a cleaner and healthier place to live in.

Our mother planet, Earth, is home    1     all creatures. Since its beginning, the Earth,     2     (go) through quite a lot, among     3    the changes of species can be the most meaningful. Not until the appearance of human kind     4    the Earth be changed so quickly. With no     5    (many) than a century after the industrial revolution, we’ve turned our blue planet into a grey one,     6    (make) more species vanish rapidly. Human may be the first species     7    (live) alone on the Earth.     8    (warn) by more severe and frequent natural disasters, human beings    9    (event) reach a consensus that we have only one Earth. Meanwhile, we’d better take instant     10    (measure) to protect it before everything is too late.

Lego is a company that makes toys in Denmark in Northern Europe. Lego's toys     1    （make） of plastic but Lego does not want customers to throw away Legos which they do not use anymore. It is testing a way to reuse Legos.

Customers in the U. S. can go to     2     (it) website. On the website, they can print a label(标签)for the mail. Then, customers can put their used Legos in a box and mail them back to Lego for free.

Lego says once they get the box in the mail, they    3    (clean )the toys. Then they will give the     4     (collect) Legos to Teach For America, a charity, which will donate the Legos to schools across the country. The toy company will wait to see if the test is     5    (good) than before. If it is, Lego may expand the program into other    6     (country).

The company usually tells its customers to keep their Legos     7     give the toys to others. When thrown away, plastic does not     8     (total) break down. It can't become     9     natural part of the soil. Instead, it breaks into tiny pieces. Birds and other wildlife might eat these pieces,     10     is bad for their health. Lego is trying to find other materials to take the place of plastic.