1 . The last time Jack Hanson took an airplane, he was a junior at the University of Vermont. To return from a term abroad in Copenhagen, he flew from Denmark, ________ in Iceland, and landed in New York.

But the next term, one of his professors asked students to ________ their individual energy usage. And when Mr. Hanson did the ________, he realized that just one leg of that international flight ________ more energy, and more greenhouse gas emissions(排放), than all the other things that year ________ — the driving and heating and lighting and eating and everything else.

He was ________. “I just couldn’t ________ it,” he says. “It really is an extreme. It’s an extreme amount of energy, an extreme amount of ________.”

So Mr. Hanson decided to stop ________. Since then, he has traveled by train and bike and car, and has even written a song about the ________ of getting home to Chicago on an overnight bus. But he has not been on an airplane.

And he has never found travel more ________, he says. He knows that some people find this hard to ________, including many friends and family members. They decide Mr. Hanson’s approach is ________.

Go more ________, and travel begins to return to what it once was: a slow change of one place to another, a sense of space, an unwinding of time.

2 . This past summer I set out on a journey to Canada’s Arctic. When I left I was wrapped in a blanket of uncertainty and ______.

But when I first met the group members, I knew I didn’t have anything to ______. The group was amazingly ______ and I was soon part of a big family boarding on an amazing ______!

Approaching the Arctic, I was repeatedly ______ with its unusual largeness and its beauty. There I flew over vast glaciers (冰河) and stood on the frozen Arctic Ocean, ______   polar bears walk in search of seal holes, and _______ wait for a meal.

However, I also learned the pollutants carried by ocean from far away have a negative ______ on all Arctic inhabitants. And global warming has put polar bears at ______ because a warmer climate means that they have a shorter time to ______ seals on the ice.

During the journey, I talked with some ______ scientists about the ruins of homes once ______ by the ancient Thule people. I made good friends with people from different parts of world.

The Arctic is a land of incredible beauty which ______ to be preserved. I’ve learned why it is so important to ______ it. This journey has made me more determined to try to ______ that I do not leave negative or harmful footprints on either Earth or its people.

3 . 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 ____________ .

5 . 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.

8 . These days, kids seem to spend most of their time on the smart phones or the video games. It’s _________ to be a bit pessimistic (悲观的) about their future. But if you look closely, there are some young minds that are trying to solve_________ world problems.

Jackson _________ away “Blessing Bags” for the homeless in Chicago: snacks, socks and other things. Jackson started his _________ at 9 years old.

In Bali, Melati and Isabel began a campaign to _________ the beaches and keep their country far from plastic pollution in 2008. Bali is now plastic-free. But they don’t _________. They are focusing on the rest of Indonesia.

Ryan was 7 years old when he _________ Ryan’s Recycling. He collected over 200, 000 bottles and cans a year from 50 customers.

In Sierra, Kelvin started bringing _________ and a community radio station to villages by making batteries (电池). He was 13 years old. Most importantly, Kelvin _________ other children that they could make a __________.

So far, teenager Slat has __________ over $ 13 million for his project Ocean Cleanup that uses the ocean’s waves to collect plastic __________.

At age 15, Ann __________ a flashlight that uses body heat for power to keep batteries __________ landfills (填埋).

Kids around the world are raising much money for cancer research and environmental problems __________ by running juice shops, sewing dresses and selling flowers.

9 . There was no need to consult my smart-watch to know that we had climbed to an altitude of more than 4,500 meters._________discomfort serves as a warning system on the Qinghai-Tibet Plateau.

After a four-hour journey, our coach_________a parking lot in Madoi county, a sprawling herding district in the northwestern province of Qinghai. I got off and took a walk, but it felt like hard work. What seemed like a slightly dazed feeling at lower place—such as when I visited Lhasa, capital of the Tibet autonomous region, in 2019 at about 3,000 meters above sea level—had_________into a severe headache because of the thin air.

As the air pressure_________rapidly, my sunscreen bottle swelled and its_________spilled out. Trees were a rare_________. The soil was frozen. Rice tasted half-cooked.

I_________a small hotel, where about 35 doctors and journalists would stay for the next few days as part of a volunteer medical program. I was assigned a roommate, a photojournalist in his 50s. We climbed_________of stairs carrying suitcases packed with winter clothes and other necessities to_________the sunburn-producing ultraviolet. The climb clearly worsened our symptoms. We were both breathless when we reached our room.

Cracks could be seen meandering across the walls of the room, a warning sign of the quake’s destruction and a__________that the danger had not gone away.

It certainly hadn’t. At about midnight, a magnitude 4.8 quake__________the county and made my roommate and I—both __________because of the discomfort we were feeling—jump out of our beds.

We scrambled for our clothes and shoes and argued about whether we had enough time to run outside. Before we had reached agreement, the shaking had stopped. The street our room overlooked was quickly__________with people, and my sixth sense for survival told me to join those life-cherishing people downstairs, but the__________told me to stay put.

The older man and I stared at each other and then decided to creep back to our beds, but we kept our pants on, just__________.

10 . The first time ever I realized that plastic was a serious matter for our planet was during a road trip in Western Australia, almost 12 years ago.

We ________ at a supermarket along the Coral Bay coast to buy some groceries and the lady at the counter told us they didn’t sell any shopping bags in order to prevent plastic in the ________ and to help preserving the endangered turtles living in that area. After a first reaction of surprise, we ________ all our shopping in our arms and left.

This was just one of the many experiences I’ve lived that made me more ________ about my impact and pushed me to adopt different habits to live and ________ more sustainably.

Our trip to Borneo was another life-changing ________ that has strengthened my resolution to a zero-waste lifestyle. While traveling in some countries, we came to know that ________ drinking water was always a challenge. So we had to travel with our water bottle, and we ________ to avoid using plastic during our trip.

Besides, we were also ________ impressed by our stay on Libaran Island. A sustainable turtle conservation ________ and the community had made big efforts to ________ the beaches and creatively reuse plastic for ten years. Despite that, the shore is ________ daily with tons of plastic coming from the tides.

Facing this global issue ________, raised in me a feeling of sadness and anger that soon turned into ________: to do as much as possible to reduce plastic in our life. Small changes can ________ a difference!