The Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese agriculture.     1     （build）over 2,200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering     2    （achieve）is still used today.

In ancient times, the region where Dujiangyan now stands     3    （suffer）from regular floods from the Minjiang River.     4    （help）the victims of the flooding, Li Bing,     5     region governor, together with his son, decided to find a solution. Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwaters while leaving the river flowing naturally.     6    （good）still, the extra water could be directed to the dry Chengdu Plain, making     7     suitable for farming.

Once the system     8    （finish）, no more floods happened and the people were able to live     9    （peaceful）. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams,     10     the water is blocked with a huge wall, Dujiangyan still lets waterflow through the Minjiang River naturally, making the ecosystem（生态系统）and fish populations exist in peace.

China’s Liangzhu Archaeological Site     1    (declare) on the list of World Heritage sites on Saturday by UNESCO’s World Heritage Committee during its 43^rd session in Baku, the capital of Azerbaijan.

The site,     2    is located in Yuhang District in Hangzhou City in China’s eastern Zhejiang Province, showcases the civilization of prehistoric rice agriculture between 3,300 B.C.     3     2,300 B.C. The ruins of ancient Liangzhu city were discovered in 2007, and then large dam sites     4    (surround) the Liangzhu ancient city were unearthed continuously after 2009. It was     5     (official) submitted to UNESCO in 2019, hoping to win     6     (recognize) as a World Cultural Heritage Site. The site     7     (include) archaeological remains and unearthed cultural relics of the Liangzhu Ancient City as well as a wetland that covers     8     area of 908. 89 hectares in a plain river network. It is also found that the Liangzhu ancestors started to use characters about 5 ,000 years ago, 1 ,000 years     9     (early) than previously thought, according to Colin Renfrew, a retired professor of archaeology at the University of Cambridge.

The World Heritage Committee added Liangzhu to the UNESCO list    10     (encourage) better protection of the site, considered to be of “outstanding universal value” to humanity.

The iceberg     1     was for a time the biggest in the world is no more. A68, which was known to us,     2    (cover) an area of nearly 6,000 sq km when it broke away     3     Antarctica in 2017. That's like a small country. Satellites show the mega-berg has now virtually gone, broken into countless small fragments(碎片) that the US National Ice Center says are no longer worth     4    (track). Most glaciologists(冰川学家) regard A68     5     the product of a very natural process, and it has nothing to do with human-induced climate change.       British Antarctic Survey also put a couple of robots in the ocean in February     6    (study) up close some of A68's latter-day segments(碎片). One went missing soon after, and the segments    7    (actual) got stuck under the ice for two weeks before managing to free itself and continue its     8    (observe). This robot     9    (recover) in May to pull down(收集) its data. It should reveal information about     10     icebergs affect their surroundings by, for example, dumping fresh water into the ocean as they melt.

If you live in northeastern China, you expect long, cold winters. People     1    (live) in Harbin don’t just stand the cold, however, they welcome it. The city is home to the Harbin International Ice and Snow Sculpture Festival,    2    is considered to be the largest ice festival in the world. Even with temperatures usually close to zero, thousands of people head to city parks     3    (see) great ice sculptures, many bathed in colored lights.

The festival includes several thousand ice sculptures. Some of these works are the recreations of castles, historic landmarks and famous people, lit up at night in bright colors. There     4    (visitor) can climb ice stairways and go down ice slides (滑坡). They can also take part    5    sporting events, including skating, ice football     6    well as ice swimming.

The city started     7    (it) icy event in 1963 with the Ice Lantern Garden Party, a     8    (celebrate) of the tradition of creating lanterns out of blocks of ice. The larger festival     9    (begin) in 1985 and added sculptures, which have grown in number and size over the years. As it has gotten bigger, the festival has become popular outside the city.    10    (official), the festival starts on January 5th and lasts over one month.

10 . When you think of the Arctic, you imagine an icy land of pure white snow, which is considered to be the last really clean place     1    (leave) on Earth. Yet plastic trash has now reached the remote regions of the Arctic and the Alps. A team of     2    (scientist) has discovered large quantities of microplastics(微塑料) — very small pieces of plastic waste — in the Arctic snow. While microplastics have been found in sea-water, drinking water, and even in animals over     3     past several years, this is the first study to show microplastics in snow,     4     indicates it is an airborne pollutant that must be paid attention to.

The researchers state that microplastics in snow suggest that microplastics may be in the air that we     5    (breath). Therefore, it is really important     6    (assess) if microplastics also reach lung tissues.

Previous research has found that they flow over long distances and into our oceans,     7    (damage) ecosystems along the way. They start in our wastewater, when we wash clothes     8     plastic fibers. The wastewater then flows into rivers and out to sea, where they     9    (eat) by sea animals. If people then eat these animals, it means that we’re     10    (probable) eating the plastic as well.