Water goes around and around the earth in a never-ending journey     1    (call) the water cycle. The sun heats up lakes, oceans and other wet places on earth. When the water gets enough     2     (warm), it changes into vapour (蒸汽). Plants also give off lots of water vapour. After     3     (cool) off high in the sky and becoming clouds, some of the vapour falls back to earth in a new place     4     rain or snow. This cycle happens over and over again.

The ground can absorb water. If you could see the groundwater, it wouldn’t look like     5     lake or river. The groundwater is mixed in with the rocks and sand     6     lie in layers below earth’s surface.

Groundwater moves along slowly. Can you imagine     7     slowly? Maybe 1.5 kilometers in one century. Some of this water has been underground for     8     (thousand) of years. And once groundwater     9     (draw) out of the ground from a deep well by people, it may take many years for water from another place to take     10     (it) place.

On October 23^rd, 2018，President Xi Jinping announced the opening of the Hong Kong– Zhuhai-Macao Bridge (HZMB) at an opening ceremony in Zhuhai, Guangdong province.

The HZMB,     1     (locate) at the waters of the Lingdingyang of Pearl River Estuary, is a huge sea crossing, linking Hong Kong and Macao to the Chinese mainland city of Zhuhai. As the world’s     2     (long) sea-based project, the 55-kilometre bridge is the result of five years of research and another nine years of building. It has been described as one of the “seven     3     (wonder) of the modern world” by the Guardian.

The project     4     (make) up of a 22.9-kilometer-long main bridge, a 6.7-kilometer-long tunnel and an artificial island off the bridge. It is designed with     5     service life of 120 years. It can withstand a strong wind equal     6     a maximum Beaufort scale 16. The bridge’s engineers had to consider many environmental factors to protect the     7     (surround) environment while building the bridge. Chinese white dolphins, an endangered species that lives in the area,     8     (be) a particular concern.

The HZMB will make     9     much more convenient to travel between the three areas it connects. It will bring people in Hong Kong, Macao and Guangdong within a “one-hour living circle”,     10     is expected to attract more visitors to the Guangdong-Hong Kong-Macao Greater Bay Area. It will be a transport link as well as a social, economic, cultural, and tourism connection among the three areas.

Comets are among the most beautiful and interesting     1    (sight) in the universe. For centuries, people     2    (show) great interest in studying them. In 1682, Edmund Halley, an astronomer, noticed a comet that was especially bright and large. Based on his calculations, Halley predicted that this bright comet would return in 1758 or 1759—this was about 75 years     3     he first saw the comet. The comet really returned on time and it was named “Halley’s Comet” in honor of Edmund Halley.