During the Tang Dynasty, poet Li Bai wrote a poem about the tough journey to Shu, comparing it to scaling the vast blue sky. The Shu Roads are named     1     the ancient state of Shu. The builders of the expressway     2    (link) Jigzhi County in Qinghai Province to Barkam County in Sichuan Province know how complex it is to build a road in the region.

Extending for 219 kilometers, the expressway lies at     3     height of over 3,300 metres. This means that the annual average temperature is just 1.4°C, and can drop as low as -36℃. Since the construction began in 2020, this extreme climate     4    (limit) work to roughly six months a year. The     5    (hard) section was the 5.5-km Shenzuo tunnel, running through weak and jointed rock masses and     6    (exceptional) complicated land conditions. Ma Kelin, the only female project manager, has learned a tough lesson since she joined the project. It took her over a month     7    (recover) from vomiting and breathlessness.

The expressway, with an     8    (invest) of 30.2 billion yuan, will open to traffic by the end of next year. Many of those     9     live along its length are waiting, expecting it to contribute to economic development. The local authority plans an area of 12 square kilometers for potential     10    (tourist) attracted by the new road.

Three million years may seem like a long time. But when you consider that planet Earth is more than 4.5 billion years old, it is a pretty short period of time.

The blue whale,     1     (weigh) more than even the biggest dinosaurs, is the largest animal that has ever lived. They can grow     2     30 meters long and be as heavy as 130,000 kilograms.     3     for millions of years, they were not nearly that large, scientists say. “All of a sudden — ‘boom’— we see them get very big, ” scientist Nick Pyenson said. He and other     4     (researcher) recently published an article on whale size. “It’s like going from whales     5     size of minivans (面包车) to longer than two school buses, ” Pyenson added.

The scientists believe that a change in the Earth’s climate caused whales     6     (get) so large only about 3 million years ago. This change led to food becoming more     7     (easy) available. An oncoming ice age made the ocean water cold and brought more nutrients, resulting in more food for large whales. Whales     8     were able to quickly eat a lot of food survived, and got     9     (large). Over the next three or four million years, the blue whales grew 10 times bigger than they     10     (be), the scientists say.

Despite occupying a relatively small area, rainforests have an important role to play in maintaining the world and they are home to a rich     1     (various) of medicinal plants, birds and animals.

As the lungs of the planet, rainforests have their own perfect system,     2     ensures their own survival. The tall trees make a canopy (顶篷) of branches and leaves that protect themselves, smaller plants and the forest animals from heavy rain, intense dry heat     3     (release) from the sun and strong winds.     4     (amazing), the trees grow in such a way that their leaves and branches, although close together, never actually touch     5     of another tree. Scientists think this is a deliberate way     6    (prevent) the spread of any tree discases. The ground floor of the forest is not all twisted leaves and bushes,     7     a fairly clear land. It is where leaves transform     8     food for the trees and other forest life.

Worryingly, rainforests around the world are disappearing at     9     alarming rate. A few thousand years ago, rainforests     10     (cover) as much as 12 per cent of the land surface on Earth, but today this has fallen to less than 7 per cent.

Jiuzhaigou is officially known as Jiuzhai Valley in English,     1    is a nature reserve in the north of Sichuan Province. It is known as the habitat of giant pandas although it is extremely hard to see a panda in the park and mainly for its many multi-level waterfalls    2    colorful lakes. It    3    (become) a UNESCO World Heritage Site in 1992.

    4     (lie) 350 km north of Chengdu, Jiuzhai Valley offers    5     (impress) views of lakes, waterfalls, and mountains. The name means “Valley of Nine Villages”, coming from the 9 ancient Tibetan villages that call it home. Its     6    (high) point is 4,700 m above sea level, with the main sightseeing areas between 1,980 m and 3,100 m.

The park is the natural habitat for the giant panda and the Sichuan golden snub-nosed monkey (金丝猴). However, because of the park’s size and    7    number of tourists, the chances    8     (see) them are slim. About 20 pandas reportedly live within the park.

For environmental protection reasons, no personal transport, not even bicycles,     9    (permit) within the park. However, with a bus pass you can take a bus to all of the sites within the park. Every few minutes a bus will come to a site to pick up the    10    (passenger).

More than 10,000 years ago, people in Mexico and Central America gathered and ate the fruit of wild avocado (牛油果) trees and    1    didn’t take long before they started to plant this high-fat, tasty food.

The name “avocado”    2    (be) from an Aztec word, ahuacatl, which refers to the shape of the fruit. The earliest evidence of human    3    (consume) of avocados is the seeds, or stones, found in Coxcatlan Cave in the Tehuacan Valley, Mexico,    4    have dated back to around 8,000 BCE. The high oil content of the avocado’s green flesh would have made the fruit a valuable addition    5    the prehistoric diet.

Domestication of the avocado soon followed, with the trees    6    (plant) in Mexico and Central America. By the time the explorer Christopher Columbus    7    (reach) South America in 1492, avocados were being consumed as far south as Peru. Today, Mexico is the world’s leading avocado producer, and the fruit is also    8    important crop in the US state of California, the Dominican Republic, and Indonesia.

With an amazing flavour, buttery flesh, and high nutrient content, the avocado has enjoyed a recent rise in popularity, and people continue to find innovative ways    9    (enjoy) it. It is perhaps most famous as the main ingredient of salad, but in Latin America avocados are still    10    (wide) used to garnish (搭配) chicken and potato soup.

The Great Barrier Reef is one of the seven wonders of the natural world. Pulling away from it and viewing it from a greater distance, you can understand why. The marine park     1     (stretch) over 3,000 km almost parallel to the Queensland coast. The reef, between 15 kilometers and 150 kilometers off shore and around 65 km wide in some parts, is a gathering of brilliant, vivid coral     2     (provide) divers with the most spectacular underwater experience     3     (imagine).

A closer encounter with the Great Barrier Reef’s impressive coral gardens reveals many     4     (extreme) amazing underwater attractions,     5     include the world’s largest collection of corals, coral sponges, rays, dolphins, over 1,500 species of tropical fish, more than 200     6     (type) of birds, etc.

The reef is     7     breeding (繁殖) area for humpback whales, migrating from the Antarctic and is also the habitat of a few endangered species including the Dugong(Sea Cow) and large Green Sea Turtle. In     8     (recognize) of its significance, UNESCO listed the Great Barrier Reef     9     a World Heritage Site in 1981.

Because of     10     (it) natural beauty, both below and above the water’s surface, the reef has become one of the world’s most sought-after tourist destinations.

Sayram Lake, known as a pearl on the mountain, is the     1     (large) and highest alpine lake in the Xinjiang Uygur autonomous region. The lake lies in a mountain basin in the western part of Tianshan Mountain.     2     is the only way to Ili prefecture.

In ancient China, the lake     3     (call) the “clean sea.” It is also known as the “Atlantic Ocean’s last teardrop,” because it is the farthest place     4     the warm and humid (湿) air current of the Atlantic Ocean reaches.

    5     (locate) 2,073 meters above sea level and measuring 30 kilometers long and 25 kilometers wide, the lake covers     6     area of 460 square kilometers. The main source of the lake is ground water, in addition to some snow and river water. The lake rises     7     3 to 5 centimeters every year. Its area also     8     (continue) to grow.

The water in the lake is clear and peaceful,     9     (attract) flocks of ducks and swans. Flourishing cedar (雪松) trees cover the whole mountain. Herds of horses and sheep graze on the grassland. The lake has become a top     10     (choose) for lovers to take wedding photos and spend their honeymoons.