The United States is a country of immigrants. It is a place where people from all over the world come to build a better life. Some immigrants bring their families. Some bring a few of their favorite things. Others come alone with nothing but determination. One thing that every immigrant brings with them is their culture.

    American immigration began in 1607 with the colony (殖民地) of Jamestown. In 1620, another group of people left England to build a settlement in America. They wanted to go to a place where they could practice their religion freely. Then many more people left their homes in Europe to build a better life in America. Many also came to America from Africa. By 1770, more than two million people had moved to America. Later on, more people came to the United States than ever before.

    In cities all over America, you can see different cultures that formed this country. Many things that you may think of as being “American” are actually from a foreign culture. Some of the best examples of this are the foods people eat. Pizza and spaghetti are foods that all Americans know and love. But both of them are from Italy. Baseball is an all-American sport. But the hot dogs that people eat during the game are a type of food that was brought to America by German immigrants.

    Over time, pizza and hot dogs have become a part of what is considered to be American food. In the same way, different groups of people have come together to define what an American is. An American can be a person of any background. An American can be of any faith. An American can be of any skin color. They can speak English clearly. They can speak English with an accent. Each new immigrant adds something new to American culture. It will keep changing as more people come to this country.

    Humans have launched themselves into the outer space. They've landed on the moon. They've built habitable space stations that orbit the Earth. The next giant leap for mankind is to reach another planet – specifically, Mars.

    The problem is that it's no easy task. The planet is 586 times further away from the Earth than the moon, and it'll take around 180 to 220 days to reach Mars, depending on where each planet is in its orbit. Such long periods in space have suggested many potential health problems, including hormonal changes, skin conditions, and muscle and bone deterioration (损耗).

    Here's where some furry friends come in. A wide range of animals have been in space, from fruit flies and spiders to cats, and dogs. Such experiments began as far back as the late 1940s in first tests to see if living things could withstand the extreme g-force (重力) of a rocket launch.

    Mice continue to play a very important part in space experiments, mainly because the animals make excellent test subjects. They're small, which makes them inexpensive and easy to care for. In addition, their size and short life span make it possible to do the equivalent of several human years of tests in a much shorter time. Finally, because mice are mammals, they share many common characteristics with humans in terms of genetics, biology and behavior.

    Astromice have hit the headlines recently, as a team of scientists led by Betty Nusgens, professor of biology at the University of Liege in Belgium, found that the mice suffered a 15 percent thinning of their skin after 91 days aboard the International Space Station (ISS).

    This experiment was part of a wider NASA mission (任务) called the Mice Drawer System (MDS). The Italian Space Agency developed the facility, which allows six mice to be housed, monitored, and automatically fed and watered aboard the ISS, among which three survived during the mission.

    The mice have participated in 20 separate experiments, to study such effects as osteoporosis (骨质疏松症), anemia (贫血) and heart health.

    Results for the 20 experiments are coming in gradually. But it's clear that mice continue to play an important role in the ongoing quest to conquer the final frontier.

    Our brains work in complex and strange ways.There are some people who can calculate the day of the week for any given date in 40,000 years,but who cannot add two plus two.Others can perform complex classical piano pieces after hearing them once,but they cannot read or write.

    Dr.J.Langdon Down first described this condition in 1887.He called these people idiot savants.An idiot savant is a person who has significant mental impairment（损伤）,such as in autism（孤独症，自闭症）or retardation.At the same time,the person also exhibits some extraordinary skills,which are unusual for most people.The skills of the savant may vary from being exceptionally gifted in music or in mathematics,or having a photographic memory.

    One of the first descriptions of a human who could calculate quickly was written in 1789 by Dr.Benjamin Rush, an American doctor.His patient,Thomas Fuller,was brought to Virginia as a slave in 1724.It took Thomas only 90 seconds to work out that a man who has lived 70 years,17 days,and 12 hours has lived 2,210,500,800 seconds. Despite this ability,he died in 1790 without ever learning to read or write.

    Another idiot savant slave became famous as a pianist in the 1860s.Blind Tom had a vocabulary of only 100 words,but he played 5,000 musical pieces beautifully.

    In the excellent movie Rain Man,made in 1988 and available on video cassette,Dustin Hoffman plays an idiot savant who amazes his brother played by Tom Cruise,with his ability to perform complex calculations very rapidly.

    Today we more clearly recognize that the idiot savant is special because of brain impairment.Yet not all brain impairment leads to savant skills.Some studies have shown that people who have purposeful interruption of the left side of the brain can develop idiot savant skills.However few people wish to participate in such experiments.There are many excellent reasons for not undergoing unnecessary experimentation on one's brain.The term idiot savant is outdated and inappropriate.Virtually all savants have a high degree of intelligence and are thus not idiots.

    The world's first luxury space hotel, Aurora Station, was announced Thursday at the Space 2.0 Summit in San Jose, California. Developed by US-based space technology start-up Orion Span, the space station will host six people at a time, including two crew members, for 12-day trips of space travel. It plans to welcome its first guests in 2022.

    "Our goal is to make space accessible to all," Frank Bunger, CEO and founder of Orion Span, said in a statement." Upon launch, Aurora Station goes into service immediately, bringing travelers into space quickly and at a lower price point than ever seen before."

    While a$10 million trip is outside the budget of most people's two-week vacations, Orion Span claims to offer an authentic astronaut experience. "It has taken what was historically a 24-month training to prepare travelers to visit a space station and streamlined(精简)it to three months, at a fraction(小部分)of the cost," says Bunger. During their 12-day adventure, the super-rich travelers will fly at a height of 200 miles above the Earth's surface in Low Earth Orbit, where they will witness incredible views of the blue planet. The hotel will orbit Earth every 90 minutes, which means guests will see around 16 sunrises and sunsets every 24 hours.

    Activities on board include taking part in research experiments such as growing food while in orbit, which guests can take home for a super-smug souvenir, and soaring over their hometown. Guests can have-live-video chats with their less-fortunate loved ones back home via high-speed wireless Internet access and, upon(return to Earth will be greeted with a specially arranged hero's welcome. While enjoying the thrills of zero gravity, the travelers will be able to float freely through the hotel, taking in views of the northern and southern aurora from the station's windows.   Deposits are already being accepted for future stays on the space hotel.

    In the US, people prefer waiting for a table to sitting with people they don't know. This means a hostess may not seat a small group until a small table is available, even if a large one is. If you are sitting at a table with people you don't know, it is impolite to light up a cigarette first asking if it will disturb them.

    At American restaurants and coffee shops you are usually served tap water before you order. You may find the bread and butter is free, and if you order coffee, you may get a free refill.

    Most cities and towns have no rules about opening and closing time for stores or restaurants, though they usually do make rules for bars. Especially in large cities, stores may be open 24 hours a day.

    Serving in restaurants is often large, too large for many people. If you can't finish your meal but would like to enjoy the food later, ask your waitress or waiter for a "doggie bag". It may have a picture of a dog on it, but everybody knows you're taking the food for yourself.

    Supper and dinner are both words for the evening meal. Some people have "Sunday dinner". This is an especially big noon meal.

    Tips are not usually added to the check. They are not included in the price of the meal, either. A tip of about 15% is expected and you should leave it on the table when you leave. In some restaurants, a check is brought on a plate and you put your money there. Then the waiter or waitress brings you your change.

As the COVID-19 pandemic hit hard, fishermen watched their markets dry up. Restaurants-normally major fish buyers-closed or cut back orders significantly. Fishermen weren't sure if they were going to get paid for what they fished.

Meanwhile as people lost jobs, food banks started to see a great demand for services. Things were getting desperate, with long lines for food assistance in many states.

Out of these dual crises, a new idea was born. Food assistance programs across the country have started connecting with local fishermen to stock up on local seafood, many for the first time. And the arrangement seems to be helping the fishermen, the economy and those in need of healthy food.

According to Catherine D' Amato, CEO of the Greater Boston Food Bank, the network usually keeps four or five weeks of food on hand in case of emergencies. The pandemic hit, and "we found ourselves below one week of stock and going down rapidly," she says. That's because the food bank normally distributes about I million pounds of food a week, and that became 2.5 million pounds of food a week, D' Amato says. While Congress and the states have increased funding and donations for food banks during the pandemic, it hasn't been enough.

"For many years, we have been wanting to be able to work with organizations in the fishing industry," D' Amato says. But it's complicated. Fishermen catch a lot of big fish, and food banks who might take it need the products to be cut small and easy to use for customers. It also has to be fish they know and recognize. The barriers have been too high in many places to make it work. But this spring, the state department of agriculture connected the food bank with some grant makers. They talked to some local fishermen about developing a traditional New England fish soup.

The grants paid fishermen for their catch and provided money for a local manufacturer to process, freeze and deliver the soup to food banks in family-size servings. The soup is helping to feed families and keep fishermen fishing. The fishermen hope to sell it in stores soon, and Damato hopes to purchase more soup and expand into new seafood products for her customers.