As we all know, bikes are    1     (main) made of steel. But can you imagine that they can be made     2     bamboo? Do you want to know how a bamboo bike is produced? Do you want to make     3     (you) own bike with bamboo? You can do it at the Bamboo Bike Studio in New York. People there can teach you how to make your won bamboo bike.

The studio is also helping build factories in Ghana,     4     is a country in Western Africa. The factories will make cheap bamboo bikes.

Bamboo is as good as steel for     5     (build) a good bike. Marty Odlin works at the studio. He says     6     bamboo bike is the wonderful everyday bike.

In Ghana, bikes are very popular. Few people have money to buy a car. And people like to use bikes     7     (carry) most of their food and other goods.

In addition, people of Ghana are very poor and they can’t build factories to make     8     (tradition) steel bikes. But making bamboo bikes     9     (be) cheap. Odlin is planning to show the Ghanaian     10     (work) how to quickly make bamboo bikes now. He hopes that more and more Ghanaian people can have bamboo bikes.

The water on the Earth keeps moving around and around in a cycle     1     (call) the water cycle. However, the amount (数量) of freshwater in our world is not spread evenly (均匀地) across the planet. People living in cities use the most water,     2     some people have only a small amount for their     3     (day) needs.

The problem is that     4     freshwater in our world could be running out. The population in the world is growing,     5     means more and more water is being used. The climate is changing and becoming     6     (warm) than it was. This changes weather patterns, so in some places there is no longer enough rain to allow people     7     (live). Add in the problem of polluted water, and the situation becomes bad indeed.

Having water whenever we need or want is something we take for granted. Whenever we use it, we need to think about how we can save it. There are many small     8     (step) we can take that add up to big water savings! Taking shorter showers and turning off the water while brushing your teeth     9     (be) all the ways to help. As long as each of us has the sense of     10     (save) water, we can see huge changes.

Every Saturday, 73-year-old Zhao Guihua takes a special course. In a classroom located in a residential community in the city of Hefei, Anhui, Zhao and her classmates, all seniors, most     1    (wear) reading glasses, learn how to shop on their smartphones.

“We offer a course     2     teaches seniors how to use their smartphones to scan(扫描)health-tracking QR codes(二维码), buy things online, register for hospital visits, and shoot short films,” said Liu Li, who is the     3    (found) of the e-course.

Liu has been providing services for the elderly for 10     4     (year). After learning that many old people don't know about the use of digital devices(设备) in their daily lives, she     5     (start) the smartphone course in August last year to help them cross the digital divide.

Official data show that by the end of 2019, some 150 million seniors at or above the age of 60 in China hadn't had the opportunity     6    (use) the Internet.

“During COVID-19, scanning a health-tracking QR code     7     (need) when we go to a supermarket or take a bus,” said 63-vear-old learner Liu Shaomin.

Instructor Huang Zhen said the course started with the basics of smartphones and that the learners were all crazy about it. Over several months. The number of learners grew rapidly, with ages ranging     8     60 to 90.

“Now I can read news, buy train tickets and book tickets for tourist attractions on my smartphone,” Zhao said     9     (proud). “Scanning health tracking QR codes is now     10     piece of cake for me.”

The Sanxingdui Ruins in Southwest China’s Sichuan province, together with the Jinsha Ruins in Chengdu, will apply for(申请) World Cultural Heritage status(世界文化遗产).

The Sanxingdui Ruins in the city of Guanghan, are thought to be one of the     1     (great) archeological(考古学的) finds of the 20th century. The ruins     2     (cover) an area of 12 square km are believed to be the remnants(遗迹) of the Shu Kingdom, dating back some 4,800 years.

The site was accidentally discovered by a farmer     3     he was digging a ditch in the 1920s. In 1986, a large number of unique relics were found in the No 1 and No 2 pits,     4     arouse global interest.

The discovery of Sanxingdui     5    (raise) an important question about the origin of Chinese civilization(文明). Before the 1980s, it is thought     6     the birthplace of Chinese civilization was in the Yellow River Basin in north China.

However, with the discovery of important     7    (relic) in the Yangtze River Basin, including Liangzhu, Shijiahe and Sanxingdui, a new understanding came     8     being. The ancient Shu civilization     9     (represent) by Sanxingdui has been regarded as     10     important part of the origin of Chinese civilization.

David Ho is one of the most famous     1     (scientist) in the world because of his research on AIDS. He was born in 1952 and he     2     (give) the name Da-i,     3     means “Great one” in Chinese.

David was interested in life sciences so he went to Harvard Medical School.     4     was there that he first saw people who had AIDS. In     5     early 1980s, AIDS was almost unknown and David decided     6     (study) this mysterious killer disease. He discovered that the HIV virus could live in a healthy person's body for years and realized that the     7     (early) a person with HIV is treated, the longer they will live.

Because of his     8     (contribute), the lives of thousands of people have been saved. Today, his research is focused on     9     (make) a vaccine (疫苗) against AIDS. If David     10     (find) a vaccine for AIDS, he will become an international hero.

The Lantern Festival, a     1     (tradition) Chinese festival, is celebrated on the 15th day of the first lunar month. It is a continuation of     2     (celebrate) the Spring Festival.The day leads to the first full moon night of the year, and is also the night when the earth returns to spring. During the Han Dynasty (206 BC—AD 24), more than 2,000 years ago, Emperor Wen ordered that the 15th day of the first lunar month to be dedicated to the Lantern Festival. It was also a romantic festival in ancient China, providing     3     opportunity for unmarried men and women to meet.

In ancient times, young women,     4     (especial) daughters of eminent families, hardly     5     (step) out their houses. But during the Later Festival, it was a tradition that all people, including those young women, come out for lantern shows. Watching lanterns at night was just an opportunity for young women to find a man     6     appearance appealed to them. Another activity, guessing the answers     7     lantern riddles, gives young people a chance to interact with each other and know more about each other. Riddles     8     (write) on the lanterns can inspire wisdom and cater to the festival atmosphere, so many people like it very much. Eating yuanxiao on Lantern Festival is another tradition. Yuanxiao     9     (make) of glutinous rice, either solid or stuffed. It can be boiled, fried or steamed     10     (eat).