2 . When you swim on the beach and sea, have you ever accidentally drunk the seawater? How did it feel? It must have tasted salty. So, why is the seawater salty?

Seawater is water that comes from the ocean. Seawater can be salty because it contains an average salt content of 3.5%. This is also a place for the salt farmers to produce cooking salt and other salt.

Some theories explain that seawater comes from rainwater that falls and flows through rivers and estuaries (河口) where the seawater will be fully filled and again formed clouds because the steam uses the help of the sun. When we talk about this, we talk about the rainwater cycle. But when the rainwater cycle occurs, the water that passes through the river carries mineral salts. These mineral salts are obtained from various places of the land starting from rocks and soils that the rainwater flows through, these remaining mineral salts make seawater salty, so the salinity of seawater is different in each part of the world. But it is certain that seawater is salty or has high salinity.

The saltiest sea in the world is the Red Sea. There the temperature is extremely hot so that evaporation (蒸发) is greatly carried out. High evaporation, coupled with little rainfall and little input of water from the river, causes its highest level of salinity. There is also the Dead Sea, which is nine times saltier. Due to the high salinity, when you swim there, you can float. However, the Dead Sea is not a sea at all which is a lake geographically.

3 . The country’s first national park, Yellowstone, is renaming one of its largest mountains to honor indigenous people after research revealed the man it had been named after helped lead a massacre (屠杀) against local tribes. As part of the park’s 150th anniversary, officials announced the 10,551-foot high peak formerly called Mount Doane is now First Peoples Mountain.

“It is a victory, yes. Is history being rewritten and retold truthfully? I hope so,” William Snell, executive director of the Rocky Mountain Tribal Leaders Council, told NPR. His group helped advise federal officials on the name change. In an email, Snell said the change to First Peoples Mountain couldn't have come at a better time as Yellowstone officials prepare for the park’s anniversary in August.

The peak—along a range on the eastern side of Yellowstone Lake—had been named after Gustavus Doane, who helped lead the Washburn-Langford-Doane exploration in 1870 that eventually led to the park getting federal protection.

But recently, historians uncovered Doane’s role in an attack that left at least 173 Native Americans dead. Known as the Marias Massacre, Doane carried out the attack over the killing of a white fur trader. In writings, Doane cast a favorable light on the attack and even showed off about it for the rest of his life, the National Park Service said last week.

The renaming to First Peoples Mountain is part of a trend to better recognize the roles and contributions of Native Americans. It has also become a priority of the nation’s first indigenous cabinet secretary—the Interior Department’s Deb Haaland, who oversees the National Park Service—and Charles SamsⅢ, the first Native American to serve as that agency’s director.

Across the American West, many iconic representative mountains and other environmental places were named after early white settlers, mostly men and some with terrible pasts.

In Yellowstone, park officials say they may consider further changes to derogatory (贬损的) or inappropriate geographical names in the months ahead.

6 . For thousands of years, Chinese writers have travelled all over the country to take down notes about the geographical conditions of each city. Among them, well-known Chinese geographer and writer Li Daoyuan, in the Northern Wei Dynasty (386-534), composed his book, Commentary on the Water Classics, after studying the original literary version, Water Classics. He later expanded the river records to 1, 252 from the original 137.

The book is now being studied again by Professor Li Xiaojie and his team from Fudan University. They have been using drawing software and 3D modelling to recreate the waterway situations on a map based on the book description. So far, they have completed research on four rivers.

“Ancient people knew really well how to apply the power of nature to technical considerations,”Li said, giving the example of Qianjin’e, one of the most famous ancient water conservation projects in Luoyang, Henan. In order to lead the river into the city for irrigation (灌溉) in ancient Luoyang, the officials built a canal branch by separating a northwest-southeast river. However, the canal water wasn't enough to support the citizens in dry seasons. To solve that, on the northern side of the canal branch, the officials built a reservoir (水库) and a channel to lead the water to the canal branch, where the waterways would converge and flow together to the city.

In Commentary on the Water Classics, a total of 2, 800 cities are recorded with details. Still, the process of recreation takes much effort. After doing a lot of text analysis and fieldwork, the team has gradually created the model with 3D modelling software based on repeated deductions (推论).

For Professor Li, the book is not only a record of the natural landscape over 1, 000 years ago, but also a detailed description of humanity and culture and a treasure for today’s reference.

    1       (locate) in the center of Spain, the capital city Madrid is famous for its art galleries. The Prado Museum has one of the world’s     2     (big) collections of art works and paintings by Picaso     3     (exhibit) at the Reina Sofia Museum. Many people are attracted to Madrid for its exciting nightlife, but the city appeals to young people because it is home     4     the Real Madrid soccer team with many star players.