In the remote far north of Sweden, in Sarek National Park above the Arctic Circle, I wake up to the sound of the wind     1    (buffet) the cloth of my tent. In summer the sun     2    (bright) shines and never sets. Standing at the edge of the mountain, watching the Rapa River flowing through the valley below, I feel so     3    (bless) to be alive and have this rare opportunity to explore this unique territory     4     is almost unknown to the outside world.

Sarek’s mountains are covered    5     sheets of ice and they are home to the Sami, the native residents of the park. For hundreds of years,     6    (look) after reindeer was a way of life for the Sami. Today, most Sami have left their ancient cottage in the mountain valleys and live     7     modern life in villages near Sarek instead.

To keep its     8    (nature)state, except for the Sami, no one     9    (allow) to live in Sarak, and all new development is banned within the park     10    （boundary）.

The Great Wall,     1     (run) for more than 20,000 kilometers, is a historical landmark with worldwide fame, but climbing it is hard. Everyone may have some knowledge of it more or less, while only a handful may have the skill to     2     (physical) participate in its restoration (修复).

However, a WeChat miniprogram, Great Wall E-tour, is allowing every enthusiast to be a hero in a virtual world, in     3    one not just visits the Great Wall, but also protects it. So far the program     4    (attract) considerable attention and got a large fan base. Around 50,000 high definition pictures of the Xipanjiakou site of the Great Wall are used to offer users a     5    (remark) experience.

Liu Yuzhu, head of the China Foundation for Cultural Heritage Conservation, says “We made documentaries and published animated books in the past. These are popular, but the Great Wall is     6     complex structure and deserves more attention. So we tried something new.” Liu also adds “A series of     7    (program) like ours have been launched in China, with a combination     8     public education and restoration of relics through digitization.” The Great Wall     9     (list) as a UNESCO World Cultural Heritage site in 1987, the first of     10    (it) kind in China.

As a Chinese, I feel extremely proud.

Goldfish may look small and cute in your home, but in the wild, it’s a different story. Releasing them into your local stream or lake is     1     bad idea. Right now, Washington State     2     (fight) off an invasion (入侵) of goldfish! Thousands of goldfish are living in the West Medical Lake in large     3     (number) and are crowding out the native fish population. How did this happen? The Department of Fish and Wildlife thinks a few irresponsible pet owners are     4     (blame). And while the goldfish may have cost the owners a few dollars, this mess is going to cost the state about $150,000 to try to remove these harmful fish. But this isn’t the only place     5     this is happening. Goldfish are invading lakes and streams worldwide, and it’s all our fault.     6     you think you’re doing the goldfish a favor by releasing it, you’re wrong! Instead, you’re setting the stage for a(n)     7     (ecology) disaster, which could threaten hundreds of other species. It turns out that goldfish are one of the world’s     8     (bad) invasive species. They introduce diseases that destroy the     9     (delicate) balanced ecosystems wherever they go. And they aren’t happy to stay in one place and will travel across many bodies of water. So     10     (think) twice before throwing that goldfish away.

When Peter Sänger and Liang Wu got together, it     1     (strike) them that they must be long-lost friends. Both firm advocates in the fight     2     air pollution, they believe that if you can't measure it, you can’t beat it. That’s     3     they founded Green City Solutions: “The solution to quantifiably improve city air.”

Their invention — the City Tree — acts as an air purifier — an interesting     4     (add) to urban trees and green spaces. Rooted in science, air pollution can     5     (eat) by the vertical flat-paneled (平面的) “trees” dotted around cities across Europe, while the “trees” also act as seats for pedestrians. Sänger and Wu’s vision is for a world in which people in cities can live     6     (healthy). They long to create living conditions that allow all people around the world to permanently have cleaner air     7     (breathe).

Using remote technology, the CityTree combines     8     air-purifying feature of moss with remote technology to increase the air flow through the “trees”. This allows them to “suck up” and clean more air than normal, and the amount they filter can be increased     9     (depend) on pollution levels at different times of day.

The German green-tech start-up is now funded by the European Commission to set up a CityTree network of 15 brand new units and test it in a     10     (science) way in Berlin's pollution hotspots next year.