2 . It is likely that on American TV shows you at times will be attracted by rubber balls on people’s desks.     1     People can squeeze them when feeling stressed out. It’s believed that by concentrating on the act of squeezing, they can let go of the negative energy in their bodies.

Indeed, stress is a big problem for many people.     2     In fact, the rubber stress relief balls that are so popular today in the US are believed to date back to ancient China. Back in the Han Dynasty (206 BC–AD 220), soldiers used walnuts to get rid of stress. By squeezing them during moments of anxiety, soldiers were able to calm themselves down before going into battle. And in the Ming Dynasty (1368–1644), ordinary citizens—not just soldiers—developed the habit of rolling two walnuts, or balls made from iron or stone, around in their hands.     3     And today, we have many gadgets (器具) and toys that are designed to reduce stress in addition to stress relief balls. One example is the popular fidget spinner (指尖陀螺).     4     You have to spin the gadget around. There’s also the fidget cube, which features different “gimmicks (机关)” on each side of the cube. You can click, spin, pull, push and rotate different parts of the cube.

    5     But perhaps we should take them more seriously. “After all, the history of stress balls is a history of modern-day coping (应对),” reporter Nadia Berenstein wrote for Woolly magazine.

A fan can drive summer heat away and help bring a cool breeze (微风).     1     ancient times, the Chinese fan has been carrying artistic and unique     2     (nation) style. China has always been regarded as “the kingdom of fans”.

The fan first appeared in China about 3,000 years ago, in the Shang and Zhou dynasties. In the early period, the fan was called “the fan of honor”,     3     (serve) as the symbol of etiquette (礼仪).

After the Qin and Han dynasties, the main     4     (shape) of fans were square, round and hexagon (六边形). The materials used to make fans     5     (be) mainly silk. People called the silk fans “court fans”    6     they were often used in royal court. The person     7     held the silk fan always looked gentle.

During the Sui and Tang dynasties, the common fans were round fans, feather fans, and some paper fans. The folding fan     8     (gradual) became popular after the Song dynasty. In the Ming and Qing dynasties, the folding fan was popular in Zhejiang, Suzhou and Sichuan. Then the     9     (popular) of writing poems and drawing pictures on the cover of a fan was rising. Later, this skill     10     (introduce) to Europe and other parts of the world.

6 . Scientists from the University of Texas at Austin have finally solved the mystery of a huge fossil that has been unlabeled and unidentified sitting at a Chilean museum for almost a decade. The relic, which looks like a deflated football, is the largest known soft-shelled egg from a marine reptile that lived on the earth over 66 million years ago. Measuring more than 11 by 7 inches, it is also the second-largest egg belonging to any known animal, only behind the now-extinct elephant bird.

The rare fossil named “The Thing” was discovered inside a rock formation in Seymour Island off the coast of Antarctica in 2011 by a team of researchers including David Rubilar-Rogers. Over the years, the paleontologist at Chile's National Museum of Natural History has showed the strange fossil to every geologist that came to the museum. However, no one was able to identify “The Thing's” origin until Julia Clarke, a professor at UT-Austin's Jackson School of Geosciences, visited in 2018.

“I showed it to her, and, after a few minutes, Julia told me it could be an egg!” Rubilar-Rogers said.

To confirm Clarke's suspect, Lucas Legendre, a student at UT-Austin who led the study, examined the fossil under a microscope. Sure enough, he found several layers of membrane, confirming that the fossil was indeed a soft-shelled egg, similar to the obvious, quick-hatching eggs laid by some modern-day snakes. “The shell is very thin,” said Clarke.

The fossil's identification led to an even bigger mystery — what animal could have laid an egg this size? After considering several potential parents, the researchers concluded that the egg was laid by an ancient marine reptile like a mosasaur. The fact that the rock formation where the egg had been found had fossil evidence of baby mosasaurs and the offspring of other marine animals further strengthened their theory.

By the Shang Dynasty (around 1600-1046 BCE), these symbols     1     (become) a well-developed writing system. Over the years, the system developed into different forms, as it was a time     2     people were divided geographically,     3     (lead) to many varieties of dialects and characters. This,     4    , changed under Emperor Qinshihuang of the Qin Dynasty (221-207 BCE).

The 1918 Spanish flu was the most deadly outbreak in history. It was caused by an HIN1 virus found in genes of birds’ origin. Although there is no     1     (universe) agreement regarding     2     the virus actually originated, it was first identified in the army in the United States.

It     3     (estimate) that about 500 million people or one-third of the world’s population of that time became infected with this virus. The number of     4     (death) was reported to be at least 50 million worldwide with about 675,000     5     (occur) in the United States. The death rate was high in people younger than 5 years old, 20-40 years old, and 65 years and     6     (old). The high death rate in healthy people, including     7     in the 20-to 40-year-old age group, was     8     unique feature of this disease.

    9     no vaccine to protect against influenza infection and no medicine to treat secondary bacteria infections, control efforts worldwide were limited to non-medical methods, like separation, quarantine, good personal hygiene, and ban on public gatherings, which were applied in     10     (heavy) infected areas.