There are many idioms in English. An idiom is a phrase that we can't understand from the meaning of each word. The following are some of them.

As the crow flies

    When a bird flies from place to place, it takes the most direct route. But when people drive, they have to follow roads and often go farther. When people give a distance "as the crow flies", they mean the shortest distance between the two points, not the distance you would have to travel by following roads.

    As Dan and his mum drove along the river, they could see the beach on the opposite side. Dan asked "How far is it to the beach?"

    "It's only about a quarter of a mile as the crow flies" his mother said.

Blow hot and cold

    In one of Aesop's Fables, a man blows on his fingers to warm them up and then blows on his soup to cool it down. In both cases, the man is opening his mouth, but what comes out is different. If a person says one thing and later says the opposite, we say that the person is blowing hot and cold.

    "Is Felicia going to try out for the soccer team this year?" Stacy asked.

    "I don't know," Tricia replied." Last week she was saying yes, but this week she's saying no. She's really blowing hot and cold."

Break the ice

    Nowadays people use the phrase to refer to ending an awkward silence by beginning a conversation.

    It was the first day of summer camp. The four girls began to make their beds in silence. None of the girls knew each other, and no one knew what to say. Finally, one of them broke the ice by saying" Hey, where's everybody from?"

Bury the hatchet

    In native American culture, when two nations agreed to end their war, they buried the hatchet. So to bury the hatchet is to make peace with someone else.

Colin could not excuse his sister for breaking his tennis racket. Finally, his sister said, "Colin, can't we bury the hatchet?"

    What might the future be like? Here are some predictions: things to come, things to go.

    Spring Festival, the most important Chinese holiday when everyone returns home has caused headaches for millions of Chinese. More than 2 billion people travel at the same time, making getting travel tickets and the journey difficult. But in 28 years, Spring Festival travel may not be a problem at all. China plans to build more than 120,000 kilometers of railway and a fast transportation network that will serve 90% of the population by 2020.

    And because most of China will be cities, people will not have to go to other places to find a job, so it will no longer be a problem.

Newspapers will come to an end in 2043. In the future, digital newspapers will be sent to personal web tools through Internet. Readers can discuss topics with journalists and editors. Information will move faster.

    Oil is running out faster than expected. But scientists have found something else for oil as fuel. Coal, natural gas, solar power, nuclear power and even water can take the place of oil as sources of energy.

    Schools will go electronic. Computers will be important and popular among the students. Everything will be in the computer and students will not need to bring books to school. They will find information on the Internet. A computer will be the students ‘library, schoolbag and connection to the outside world. There will be robot teachers, who will check homework on computers and communicate with the students' parents through e-mail. And school buses will be like spaceships, comfortable and safe.

    Flying insects are polluting new environments by eating microplastics in polluted waters and carrying them through the air, a new study has found.

    UK researchers found that microplastics -- pieces of plastic less than 5 millimeters in size -- remain in the bodies of mosquitoes and other waterborne insects even after they become flying adults.

    The findings mean that pollution from plastics being dumped into our oceans is being carried into the air, and raises concerns that birds and other creatures that eat the insects are also being polluted.

    The team from the University of Reading in England and Queen's University in Belfast, Northern Ireland, inserted two minuscule pieces of polystyrene, each weighing just over one gram per cubic centimeter, into young mosquitoes and observed the insects throughout their life cycles. They found that the particles did not disappear from the mosquitoes' systems after the insects moved between life stages and started to fly, and were present inside the fully formed insects. “When the microplastics become the adults, it represents a potential aerial pathway to pollution of new environments,” the authors wrote in the study.

    “Thus, any organism that feeds on terrestrial life phases of freshwater insects could be affected by MPs found in aquatic ecosystems ( 水生态系统),” they added, using an abbreviation for microplastics. Freshwater insects such as mosquitoes are eaten by birds, amphibians, insects and fish, according to the Environmental Protection Agency in the United States. More than 150 million tons of plastic are floating in the world's oceans, with an additional eight million tons entering every year, according to the World Economic Forum. Plastic can be eaten by fish, birds and marine mammals, and can damage marine ecosystems such as coral reefs.

    “This disturbing study raises real concerns about the spread of plastic pollution: it really is present everywhere, not just the marine environment,” said plastic pollution campaigner Emma Priestland from the charity Friends of the Earth.

    “Knowing that plastic can be moved from the larval stage to the adult mosquito, which then serves as food to a multitude of larger animals, highlights the urgency with which we need to.”

    A study from 2015 estimated that the total amount of floating plastic in the oceans could triple by 2025.

    Being an astronaut sounds cool, doesn't it? In space, they get to do some pretty amazing things, like floating (漂浮) in zero gravity(重力).

    However, there are also plenty of things that astronauts can't do because of their weightless environment(环境), and that's very sad. What's worse, they can't even let their sadness show -because it's impossible to cry in zero gravity.

    Of course, astronauts can still produce tears. But crying is much more difficult in space, reported The Atlantic in January. Without gravity；tears don't flow downward out of the eyes like they do here on Earth. This means that when you cry in space, your tears have nowhere to go — they just stick to your eyes.

    In May 2011, astronaut Andrew Feustel experienced this during one of his spacewalks. "Tears," he said, "don't fall off your eye...They just kind of stay there."

    Besides making your vision(视觉) unclear, this can also cause physical pain. Back on Earth, tears are supposed to bring comfort to the eyes. But that's not the case in space. The space environment dries out astronauts' eyes, and when tears suddenly wet the eyes, it can cause pain rather than comfort. "My right eye is painful like crazy." Feustel told his teammate during the walk.

    Since gravity doesn't work in space, astronauts need some extra help to get rid of the tears. Feustel chose to rub his eyes against his helmet to wipe the tears away. Another choice is to just wait — "When the tears get big enough they simply break free of the eye and float around," astronaut Ron Parise told The Atlantic.

    There are lots of small things — things like crying — that we are so used to on Earth, we usually take them for granted, until they become a problem in a totally different environment, like space. There, astronauts can't talk to each other directly. They also can't eat or drink in normal ways. They can't even burp (打嗝), because there is no gravity to hold the food down in their stomach. If they do burp, they just end up throwing up (呕吐) everything in their stomach, according to the UK National Space Center.

    Thus, perhaps it's only space explorers who can honestly say, "Gravity, you're the best."

Our Museums, Galleries, and Zoo

19 world-class museums, galleries, and a zoo

The Smithsonian offers eleven museums and galleries on the National Mall and six other museums and the National Zoo in the greater National Capital Area. In New York City, we invite you to tour two museums in historic settings.

Not near a Smithsonian museum? Look for exhibitions and museums in your community. Here we have listed some places to visit:

Tips & Guidelines:

    Stop at any Smithsonian museum information desk where friendly and knowledgeable staff and volunteers can assist you in planning your visit.

    Service animals are welcome at the museums and the National Zoo. Pets are not permitted.

    Lunches should be properly closed or stored in lockers during your visit.