The advice to “let go” of negative（消极的）feelings is repeated in yoga classes and self-help books. Now a new study suggests it really brings lasting health advantages. Those who had a hard time getting over daily troubles had more physical health problems ten years later.

If you are likely to think over daily troubles—running through every “what if” and “if only”—it makes you feel that’s a big deal. Maddux said, “You probably find you feel even worse after a night of thinking. If that cycle is repeated over time, it will wear you down.”

The study results are based on 1,155 people who took in a national health study. Each day, the people described their feeling changes over the past 24 hours. During the 10-year mark, only 17 percent of the people have no physical health problems, and only 20 percent are satisfied with their physical strength. But those who always say they have negative feelings because of daily troubles are more likely to have the physical problems, the finding showed.

People can be likely to have bad feelings for a longer time for many reasons. For some people, worries or anger could drive it. Many others naturally have a more nervous feeling or are likely to think over and over again. But even if you are born to be negative, that can be changed.

“Yes, it’s hard to ‘let go’,” Leger said. But people can develop that skill through practice, in which you train the mind to pay attention to the present, rather than worries about the past.

“Paying attention to the present, especially on things you are grateful for, has been shown to have several advantages,” Leger said.

Two copied volumes（册）of an ancient Chinese encyclopedia sold for more than $9 million at auction（拍卖会）on Tuesday. The encyclopedia, known as Yongle Dadian, was first ordered to make by Yongle Emperor（皇帝）, the third ruler（统治者）of the Ming Dynasty（朝代）from 1402 to 1424. More than 2, 000 scholars（学者）worked on the encyclopedia between 1404 and 1408.

Yongle Dadian is the largest encyclopedia in the world. In 1562, Jiajing Emperor, the 11th Ming Dynasty ruler, ordered two copies of the encyclopedia to be made, but the original（最初的）was lost because of many wars, thefts（盗窃）and fires that happened under the Ming Dynasty（1368—1644）.

While the two volumes sold on Tuesday are copies, they are very rare（稀有的）, with fewer than 400 volumes left in the world. The books, which were 20 inches by 12 inches, were written in red and black ink（墨水）on paper. Although printing techniques（技术）had been developed at that time, the encyclopedia was written by hand because of its length. Finally, the two volumes were bought and the final price was $9. 428 million. Most of people were surprised at the high price.