Twin giant pandas have been born at a breeding (繁殖) center in southwestern China,    1    is a sign of progress for the endangered species as they struggle for survival due to occupation on their land by agriculture    2    industry.

The male and female baby pandas, born on Tuesday at the Qinling Panda Research Center in Shaanxi Province, are the second pair of twins born to    3     (they) mother, Qin Qin. She was also born at the center and    4     (previous) gave birth to twin females in 2020.

Chinese researchers for years have been working    5     (promote) the population of the animals, which reproduce rarely in the wild and rely    6    a diet of bamboo in the    7     (mountain) of southwestern China.

The efforts have paid off, with some captive-bred pandas being released into the wild. The population of wild pandas    8     (increase) over the past few years,    9     (reach) an estimated 1,800. About 500 others live in zoos and reserves, while the    10     (major) live in the mountainous, heavily forested province of Sichuan.

Do you know Xu Xiake? He is the     1    (famous) travel writer and geographer in Chinese ancient history. And his hometown Jiangyin is popular among tourists     2     home and abroad. Of course, ancient adventurer Xu Xiake remains the main reason     3     people come there. Up to now, his masterpiece, the Travel Diaries of Xu Xiake,     4    (read) widely.

Xu Xiake spent over three decades travelling throughout 16 provinces,     5    (describe) his explorations in his dairies in detail. His diaries belong to the category of travel literature,     6     is known not only for taking travel as its subject but also including author’s     7    (experience).

Xu Xiake was born to a wealthy father, who     8    (prefer) nature to power, and landscapes over official positions in particular. Xu Xiake took after his father. He enjoyed books on history, geography and adventure. He     9    (especial) enjoyed reading about China’s mountains and rivers. The little child decided he would see them     10    (he) one day. With this dream, he finally made it when he grew up.

There are thousands of endangered species in the world. If the rate    1    which they are dying out continues to rise, millions of plants and animals will become extinct    2    (immediate) in the next decade. The Giant Panda,    3    (know) as a symbol of conservation, might be one of them. Apart from the few pandas    4    (live) in zoos and conservation centres around the world, pandas     5    (find) only in the bamboo forest in southwest China. They are endangered as their habitats are being destroyed due to human    6    (activity). Because of conservation efforts,    7    number of pandas is increasing according to a recent survey. The news is exciting, but much still has to be done to save it from    8    (extinct). The Yangtze Dolphin is another species    9    habitat is being threatened. We must take measures to protect the Yangtze River. We should learn to exist in harmony with    10    (vary) types of wildlife.

The Future Life on Mars

Compared with the life we     1    (live) on the earth now, the future life on Mars will be     2    (total) different.

Firstly, without pollution on Mars, people will be able to drink cleaner water     3     breathe fresher air, so they will be     4    (health). The food on Mars will be different     5     our food now. People will just take     6    (pill) and drink man-made juice instead of eating bread and meat. Secondly, people will travel back to the earth or to other planets for sightseeing by spaceship. Additionally, there will be no     7    (fix) school and classrooms. Children will just fly to the classroom in the school spaceships. And people won’t work in factories or companies. They can stay at home,     8    (work) with computers. People believe       9    Mars can support life in the future. Nevertheless,     10     will take some years before these dreams come true.

The Singing Sands Mountain(鸣沙山)is located in Dunhuang in    1     (west)China. Whether you walk through the quicksand    2    slide down a sand mountain, you can hear loud noises from beneath your feet. That’s    3    it is named“The Singing Sands Mountain”. There is a spring lying between the tall sand mountains. This spring, which looks like a crescent moon(月牙),    4    (exist) for thousands of years and has never dried up. The formation and continuous existence of the Crescent Spring are greatly related to its topography (地势).

The flowing water gathers here along the landform and overflows through a porous(可渗透的) geological layer    5    (form) the Crescent Spring. Although its     6    (extreme) dry here, with the annual evaporation being more than 60 times that of the annual precipitation, the stable water source ensures a sustainable water supply to the spring.It’s also due     7    the low-lying terrain(低洼).Whenever there’s a sandstorm, it forms an upward spiral air flow between the surrounding sand mountains, sending the sand at the foot back to    8    top of the sand mountain,and saving the Crescent Spring from    9    (wallow)by quicksand.

The ancient Silk Road once passed by the Crescent Spring. And today, it has become a romantic paradise for    10     (visit).

Jane Goodall had wanted     1     (work) with animals in their own environment since she was a child. But this was not easy.     2     she first arrived in Gombe in 1960, it was unusual for     3     woman to live in the forest. However,     4    the help of her mother, she began her work with the chimps, which changed the way     5    people think about chimps. Spending years observing and recording their daily activities, Jane discovered that chimps hunt and eat meat, against what people used to think. She also discovered how chimps communicate     6    each other.     7     (work) with the chimps for years, Jane has argued that wild animals should     8    (leave) in the wild and not used for     9    (entertain) or advertisements. She has achieved everything she wanted to do, but more     10     (important), she has got the world to understand and respect the lives of chimps.

Dogs are often called “man’s best friend” and make ideal pets.

    1     most attractive quality of a dog is its faith in its owner. They always greet us when we come home and they will never leave us even     2       a desperate (绝望的) situation. For example, there was a very sick man and his dog barked and barked until the rescue team     3     (arrive).

Furthermore, dogs are strong animals     4     will protect us. Houses with dogs are considered much     5     (safe) than those with burglar alarms (防盗警报器). Not only will they stop thieves,     6     they will also guard against fire. For example, there was a serious fire and a dog managed     7       (pull) its owner out.

And     8     (final), dogs can be trained by people. Dogs can do a number of things that people can not. For example, they can find drugs, bodies, illegal DVDs and hunt down prisoners   with     9     (they) nose. They’re also used to help the elderly and disabled.

To sum up, dogs are really friendly, civilized (文明的) and loyal     10     (partner).