The Olympic Games, held every four years,are    1    extraordinary sporting event for thousands of    2    ( high)trained and talented athletes. The ancient Olympic Games began in the year 776 BCE and died out around the year 393. It was Pierre de Coubertin    3    brought the Olympics back to life.The modern Olympics were first held in 1896, in Athens.

Many well-known    4    ( athlete) achieved sporting excellence at the Olympic Games. The boxer Muhammad Ali won the light heavyweight gold medal for the USA during the 1960 Rome Olympics. Jessica Ennis-Hill won an Olympic gold medal in her home country in 2012. Just two years after giving birth to her first child, she     5    ( return) to the Olympics and won a silver medal in 2016

Chinese athletes make outstanding contributions    6    the Olympic Games. In addition to    7     ( host) the 2008 Beijing Olympics, China also ranked first in the medal table. Xu Haifeng won    8    ( we) country's first-ever gold medal at the 1984 Los Angeles Olympics. Liu Xiang became the first Asian    9    ( win)the gold medal in the men's 110-metre hurdles at the 2004 Athens Olympic Games. The Chinese women’s volleyball team won a hard-fought victory in the final at the 2016 Rio Olympic Games. Beijing has won the    10    (elect) to host the 2022 Winter Olympics.

One aspect of the COVID-19 pandemic that     1    （keep）us guessing since the early days is why some people who get the virus don’t suffer much and others become desperately ill. All the more, while the elderly, some—even centenarians— survive, whereas countless younger people,     2    immune systems are supposed to be stronger, have been seriously     3    (affect). So what factors give some people     4     stronger immune system than others, regardless     5    age?

Our immune systems slowly decline as we age. Think of a photo of yourself from ten years ago versus one     6    (take) this afternoon. “You see changes in your face, skin, and hair color,” says Insoo Kang, MD, director of allergy and immunology at the Yale School of Medicine. “It takes time. Same process with your immune system.”

The difference in the rate of decline between individuals is one of science’s big     7    (mystery). The immune system is complex, but most of us understand the basics.     8    (fortune), we won’t always be in a pandemic. But we can use this one to gain an     9     (understand) of how the immune system changes with age and how we might slow the decline and     10     (strong) our immune system in the future.

First it was pets, then fish.Now it's poultry(家禽）and pigs. The list of animals     1    （allow)to feed on insects is growing.A new EU law authorizing(授权）the use of insect protein in poultry and pig feed(饲料）came     2     force earlier this month.

Since a ban on processed animal protein was imposed in 2001 in the wake of the“mad cow”crisis, soy and fishmeal     3     (become)the base of animal feed in Europe.     4    ，their production needs lots of space and can be harmful to the environment,so feed manufacturers are looking for alternatives.Insects are just the ticket.They are raised in farms     5     require little land or water, and they can be fed on agricultural by-products or food waste such as rotting fruit and vegetables. They're also a natural fit. Most wild fish, birds and pigs eat insects.

The one thing going against them is price: insect protein is two to three times     6    （expensive)than fishmeal.Increasing production may help reduce the difference.Insect companies have worked hard.Research suggests insects may be more than mere feed,boosting growth rates and immune systems as well as filling     7     (stomach).They also offer the prospect of a green,local protein.

Poultry and pig feed are by far     8     largest animal-feed markets,but they're more     9    （compete)than food for pets or fish. This year the European Food Safety Agency has ruled that three species of insects (yellow mealworm, locusts and house crickets) are safe for humans to eat as well.     10     surprises them is that people seem less keen on the idea than chickens and pigs.

Acupuncture, a component of traditional Chinese medicine, appeared in China more than 2,000 years ago and is one of the     1     (treasure) of Chinese medicine. It functions by improving the smooth flow of life force energy,    2     (know) in Chinese as qi. The channels, through     3     qi flows from the body’s primary organs to body tissues of the skin, muscles and bones, are called meridians (经络), where most acupuncture needle points    4     (locate). In other words, the needles work by repairing damage to the basic structure of our bodies    5     (ensure) that the life force energy of qi can flow smoothly.     6     acupuncture is not enough to cure all illnesses, at least it creates a good starting point to build a healthy body.

Acupuncture can serve as     7     effective introduction to TCM therapies in other countries. It is now     8     (wide) practiced throughout the world, having reached 103 countries besides China. So far, eighteen countries have covered acupuncture under their health insurance plans, indicating wide     9     (recognize) of its effectiveness. This     10     (grow) worldwide acceptance has proved the strength of acupuncture, and this wisdom of the Chinese tradition is expected to bring health and happiness to more friends here and after in the future.

Every four years, thousands of highly trained and talented athletes gather together in the spirit of friendship, solidarity and fair play, ready to test their abilities against each other in the hope of     1     (recognize) as the best of the best. This is the Olympics-     2     extraordinary sporting event that was first celebrated about 3000 years ago.

    3     (motivate) by the Olympic motto “Faster, Higher, Stronger”, many well-known athletes,     4     male and female, have devoted themselves to achieving sporting excellence and     5     (push) the boundaries of human achievement.

The 2008 Beijing Olympics called on the whole world to join in the Olympic spirit and build a better future for humanity     6     the slogan “One World, One Dream”. In addition to hosting the Olympics for the first time, China also     7     (rank) first in the medal table. This success is     8     (true) remarkable if you consider that just 24 years before, at the 1984 Los Angeles Olympics, Xu Haifeng won our country’s first-ever gold medal. At the 2004 Athens Olympics Games, Liu Xiang became the first Asian to win the gold medal in the men’s 110-metre hurdles,     9     at the 2016 Rio Olympic Games, the Chinese women’s volleyball team won a hard-fought victory in the final.

The Olympic Games bring joy and excitement to people across the world.     10     Coubertin believed, “With the Olympic Games, each generation celebrates its advent, its joy of living. its faith in the future, its ambition and its will to ascend.”

Autumn Equinox (秋分) lies at the midpoint of autumn,     1     (divide) autumn into two equal parts. After that day, the location of direct sunlight moves to the south, making days     2     (short) and nights longer in the northern hemisphere (半球).

    3     is said in the ancient book is that on Autumn Equinox day the Yin and Yang are in a     4     (balance) power. Thus the day and night are of equal length, as are the cold and hot weather."

By Autumn Equinox, most of the areas in China     5     (enter) the cool autumn. When the cold air heading south meets the declining warm and wet air, rainfall happens. The temperature also drops     6     (frequent).

According to experts, on the Spring Equinox and Autumn Equinox, the day and night are of equal time both in the southern and northern hemispheres. Standing eggs on end,     7     traditional Chinese custom, is considered the best on this day.

But once it     8     (question) whether standing the egg had anything to do with the time. As is known now，the most important thing is to shift the egg’s center of gravity to the lowest part of the egg. In this way, the trick is holding the egg     9     the yolk (蛋黄) sinks as much as possible. For this, you’re better off choosing an egg that's about 4 or 5 days old,     10     yolk is likely to sink down.

At about the age of 65, most Californians stop working full time and begin benefiting from social     1     (secure), Medicare and their years of saving. The decision     2     (retire) is often swiftly followed by a series of lifestyle changes as retirees take advantage     3     their newly-increased liberty and accumulated     4     (finance) power.

One of the most significant changes is that they put     5     (they) current home up for sale and correspondingly move to a new residence with a better year-round climate or one nearer to their family. As these retirees begin to relocate, opportunities will come for real estate brokers. Farsighted hometown brokers will prepare for this immigration,     6     (offer) relocation services to those who move locally. The U.S. Census Bureau reports 50% of senior citizens who relocate choose to move to a new residence within     7     same community.

On the other hand, many retirees have     8     (historic) chosen to leave California for states with a lower cost of living and a more relaxed, “retirement-friendly” reputation, such as Florida, Texas and Arizona. Those with lower retirement     9     (pension) may relocate to Mexico. Brokers can be of service to these sellers or home buyers as well. They need to take the opportunity to suggest new residences in retirement-friendly communities     10     they have established contacts with cooperating brokers, and profit from fee splitting for referrals (介绍) to these relocations.

The Mid-Autumn Festival is one of the     1     (important) festivals in China. It is an evening celebration when families gather together to light lanterns, eat moon cakes     2     appreciate the round moon. On that night, the moon appears     3     roundest and brightest. The full moon is a symbol for family reunion, which is     4     that day is also known as the Festival of Reunion.

The Mid-Autumn Festival celebrations date back to more than 2,000 years ago. In the Tang Dynasty, people began to enjoy and worship the full moon     5     a custom. In the Southern Song Dynasty, however, people sent round moon cakes to their relatives as gifts in     6     (express) of their best wishes for family reunion.     7     it turned dark, they gazed up at the fall silver moon or went sightseeing by lakes     8     (celebrate) the festival. Since the Ming and Qing dynasties, the custom of Mid-Autumn Festival celebration     9     (become) even more popular. Together with the celebration appeared some special customs in different parts of the country, such as     10     (burn) incense (香), planting Mid-Autumn trees, lighting lanterns on towers and fire dragon dances, etc.