1 . How did Cape Town, South Africa, get into a Day Zero situation—when the city’s taps would go dry because its reservoirs (水库)would become dangerously low on water? The city gets its water from six reservoirs in Western Cape province, which usually ____________ during the rainy season, from May through August. But since 2015 the region has been suffering from the worst drought (干旱)in a century, and the water in those reservoirs____________ tremendously. Compounding the problem, Cape Town’s population has grown substantially, increasing ____________ . The city actually did a pretty good job by reducing leaks in the system, a major cause of water waste, and has even won awards for its ____________ policies. But the government of South Africa was slow to declare a national disaster in the areas hit hardest by the drought, paving the way for the recent ____________.

Cape Town is not ____________ . Since 2014 southeastern Brazil has been suffering its worst water shortage in 80 years,___________ decreased rainfall,   forestation and other factors. And many cities in India do not have access to municipal water for more than a few hours a day, if at all.____________ , the city of Shimla ran out of drinking water in May, urging locals to beg tourists to stay away from the popular Himalayan summer resort.

In the U.S., the situation is somewhat better, but many urban centers still ____________ water problems. Californians recent multiyear drought led to some of the state’s driest years on record. Since about half of the state’s urban water usage is for landscaping, it was able to cut back on that fairly easily. But cities that use most of their water for more essential uses, such as drinking water, may not be so ____________ .

____________ , steps can be taken to avoid urban water crises. In general, a “portfolio approach” that relies on multiple water sources is probably most ____________ . Cape Town has already begun implementing a number of water projects, including tapping groundwater and building water-recycling plants. Many other cities will need to repair existing water infrastructure (基础建设)to cut down on leakage. City leaders should be thinking about meeting long-term needs rather than just about ____________ requirements. Good organization and financial accountability are equally critical. And planning efforts should include diverse stakeholders (利益相关者)from the community. One major challenge is providing services to informal areas, which develop without any government foresight. Such regions often ____________ basic resources一a well-planned water supply among them. The global community has an opportunity right now to take action to prevent a series of Day Zero crises. If we don’t act, many cities may soon face a time when there isn’t a drop to ____________ .

In their spare time, most young people like to enjoy     1     (they)and play on their smartphones. But Li Ruxue is different. He often walks around a forest alone,     2     (isolate)himself from the outside world. “Though the lifestyle is a little bit tiring, it’s meaningful,” he often said.

In college, Li actively took part in field research. After graduation, he joined a gibbon protection organization where what he mainly needs to do is     3     (pick)up gibbon waste. The gibbon is a top-level state-protected animal     4     population is smaller than that of wild giant pandas. So over the past four and a half years, Li     5     (follow)gibbons and collecting their waste for researchers. Li said the job relies heavily on luck and     6     (persevere). But he has never regretted his choice or felt alone.

Like Li, Chu Wenwen, 27, has also worked to protect animals. As her father is engaged     7     wildlife research, Chu has long been surrounded by wild animals. She followed in her father’s footsteps. Listed as     8     first-class state-protected animal in China, the Mengxin beaver is found only along the Ulungur River in Xinjiang’s Altay prefecture.To protect them, Chu initiated the “beaver canteen” program, which     9     (eventual)attracted over 1 million internet users to donate snack money.

According to Fan Pengfei,     10     (ecology)protection as an industry can provide only a few jobs,most of which are in research institutes and nongovernmental organizations. He has seen more and more young people take part-time jobs as journalists, photographers and so on to raise public awareness of wildlife protection. “Young people are the future of the world and the future of global biodiversity conservation,” said Fan.

3 . Many poor children in Africa struggle on tuition for an education. However, a new school has been asking their pupils to pay for classes with _________.

Every week, students _________ the Akshar School are required to line up and “pay” for their classes using grocery bags _________ at least 25 pieces of plastic waste they _________ from around their homes and communities.

Parmita and Mazin, the couple _________ for the new school, were _________ to launch the campaign after witnessing their students being forced to _________ the acrid smell of burning plastic. That’s _________ before the school was opened in 2016, local families and communities _________ burned plastic waste as a means of keeping warm and fueling fires.

Now, the plastic is being collected and recycled at the school’s own recycling center. The school __________ the trash into Ecobricks by compressing (压缩) about 40 pieces of garbage into a(n) __________ plastic bottle.

Furthermore, the school’s older students can work part-time at the center as an additional source of __________.

Now the school owns over 100 students __________ the ages of 4 and 15. Since the school’s __________ curriculum has attracted more and more __________ to enroll, the couple plan on opening another 100 schools over the next five years.

5 . Oceans are an appealing target for renewable energy production. Waves produce 32,000 terawatt-hours of natural energy per year — for reference, the entire world uses around 23,000 terawatt-hours every year.

The advantages of wave power are clear.     1     Turbines produce electricity through the power of waves, making them a completely pollution-free, renewable energy source. And the amount of kinetic energy in a wave is huge that energy is used to produce electricity. There is also a lot of potential because many countries have access to an ocean that can help power their electric systems. Also, waves are hardly interrupted and almost always in movement.     2    

But the disadvantages of wave energy are serious too. Building factories or electrical wires directly on the beach might prove challenging.     3     Local fishing zones could be affected or the factories could lead to more coastal erosion. High cost is a problem too. Wave power is a rising energy technology in the early stages of development, so calculating the costs is difficult.     4     Because constant movement can lead to more breaking, wave energy factories will most likely need regular and costly maintenance.

    5     For many ocean-bordering countries, wave energy will be a great addition to the newable energy mix. The bottom line is that wave power has enormous global potential. However, the industry needs more funding and research to finalize the technology involved so that countries can begin adding wave energy to their renewable energy source.

8 . Imagine a new smartphone product. It works the same as any other smartphone, but when dropped, those cracks that appear after an annoying fall slowly begin to fade away, and the phone magically repairs itself、A team of researchers led by chemistry professor Takuzo Aida have found a way to create self-repairing plastics that can be used in smartphones, cars and other products. But their new plastics won’t only be used to create unbreakable products, but also help the fight against growing wastes harming the planet.

91% of plastic is non-recyclable and filling Earth with waste. The increasing plastic in landfills is a growing concern due to its negative environmental impact. In 2019 about only9% of plastics were recycled globally, leading Japanese scientists to seek to find plastic that can start its own formation or self-repair.

The self-repairing plastics are made by adding a tiny amount of a specialized substance into ordinary plastic to hold the monomers (单体) together by hydrogen bonds (氢键). When the new plastic is broken down by heat, instead of burning to waste, the hydrogen bonds mix and allow for the formation of special shaped monomers to create a foundation for more monomers to layer on and rebuild itself. The team found that their self-healing plastic was able to automatically repair at room temperature over an hour to regain its durability.

The team’s work suggests great prospects for the future of plastic. “The technique could lead to the development of a made-to-last plastic that does not need to be recycled,” lead professor Aida said at the conference, “and can one day be in products from smartphones to cars and even buildings.”

10 . Mount Qomolangma, meaning “Holy Mother” in Tibetan, is the world’s highest mountain above sea level. No wonder most people consider climbing to its top as one of their biggest achievements. More than 4, 000 climbers, ranging from 13 to 80 years old, have managed to reach the top. Three people from the Sherpa community hold the current record at 21 times each!

You may be surprised at these numbers but that’s just the start of it. Last year, cleanup crews collected as much as 8. 4 tons of garbage from Mount Qomolangma’s North Base Camp in Tibet at 5,150 meters. And in the regions below that level, more than 335 tons of waste was collected. What a sad fact it is that the highest mountain in the world is turning into the highest mountain of trash!

To reverse the trend, the Chinese government recently announced that it had closed the North Base Camp to tourists. From now on, ordinary tourists will only be able to travel as far as Rongbuk Monastery, about 5, 000 meters above sea level. No more than 300 climbers with special permits will be allowed to climb Qomolangma each year. They are supposed to follow stricter rules, including carrying all their waste out with them and only climbing in spring.

Despite these tough measures, it is clear that tourism has caused enormous damage to the natural environment. Mount Qomolangma is not alone. Some popular parks around the world are also struggling to preserve their environments and keep up with increased tourism. Yellowstone National Park in the U.S. has long been troubled by the overflowing trash piles. Joshua Tree National Park suffered a wave of vandalism (破坏), with graffiti sprayed on rocks and ancient trees destroyed. In order to protect the environment, the National Park Service had no choice but to close the park temporarily.

As we can see, the natural environment can be destroyed by human activities in less than five minutes, but it might take hundreds of years to recover. Now it’s time for ordinary tourists to leave “Holy Mother” alone and wait for her to restore her beauty.