外研版（2019）选择性必修二高中英语Unit 4 Breaking boundaries Part 2 Using language 同步练习

If you want to visit that doctor, an appointment before you go.

writing the composition in an hour.

When you are taking notes in class, everything that the teacher says.

his invention will make people's life more convenient.

Transportation and communication networks bring people together. Yet sometimes people themselves bring forth barriers to transportation and communication. In some countries, laws stop people from moving freely from place to place.

Over the centuries, many groups of people have been denied the freedom to travel because of their race, religion, or nationality. In the Middle Ages, for example, Jews were often forbidden to move about freely within certain cities. South Africa's government used to require black Africans to carry passes when they travelled within the country. Some governments required all civilians to carry identification papers and to report to government officials whenever they moved.

Countries set up customs posts at their borders. Foreign travellers must go through a customs inspection before they are allowed to travel in the country. Usually travellers have to carry special papers such as passports and visas(签证). Some countries even limit the number of visitors to their country each year. Others allow tourists to visit only certain areas of the country, or they may require that travellers be with an official guide at all times during their stay. Many of those barriers to travel also act as barriers to communication. When two governments have divisions on important matters, they usually do not want their civilians to exchange news or ideas freely. Countries often try to keep military or industrial information secret.

Today, people have the ability to travel, to communicate, and to transport goods more quickly and easily than ever before. Natural barriers that were difficult or dangerous to cross a hundred years ago can now be crossed easily. The barriers that people themselves make are not so easy to overcome. But in spite of all the different kinds of barriers, people continue to enjoy travel and the exchange of goods and ideas.

I was envious of my friends who stayed at school for lunch. They1 the same things as the characters in my favourite TV shows. The meals we ate at home were different. One day, a classmate asked what I ate for lunch. I 2, feeling like I'd been caught. Like most days, we'd had fried rice. "Sandwiches," I lied. My face got hot as I turned around, 3 she wouldn't ask anything more.

Still, there was one day of the year when Mom made an4 and I was allowed to stay at school for lunch. My dream would be realistic on that day. Every year, there was Chinese Day at the cafeteria to 5 Chinese New Year. "The school is honoring our heritage," Mom would say. The first Chinese Day lunch I can 6 was when I was about six. I had7 this day for weeks. When the bell rang for lunch, I rushed to the cafeteria. As I stood in line, I imagined the 8 they'd made waiting for me.

There would be9, surely—every Chinese New Year meal included fish. I could explain to my friends what Mom had told me: How the 10 for "fish" in Chinese sounded like another word meaning "abundance". There would be chicken, too, probably with the head still on, because a whole chicken for Chinese New Year 11 wholeness.

The line was slowly moving forward until 12 it was my turn. The cafeteria worker passed me my plate and I looked down. I couldn't 13 anything at all. All I did was sit there, confused. They called this "Chinese" lunch, so why had I never 14 it before? Those first few bites, I realized later, were my 15 to Chinese-Canadian cuisine.

Some scientists say there will not be enough land for Earth in the near future. So some other places should (find) by us to live. While some scientists are considering building communities on the moon and Mars, other scientists feel independent space stations could bring many more (benefit).

So what is wrong  the moon or Mars? Firstly, the distances are a problem. The moon is about 384,000 kilometres from Earth. Mars is over 55 million kilometres away. The journey to the moon takes from four to eight days,  the one to Mars takes from six to eight months. It will be both time-consuming and (danger) to get settlers to these distant places. Moreover, it takes a message up to 44 minutes to go from Earth to Mars,  (make) fast communication impossible. However, space station circling Earth is just a few hours away,  makes the trip much cheaper and communication (relative) easy. Furthermore, the absence of light at night on the moon and Mars isn't a good thing either. On a space station, however, the sun's energy can be made available (support) mankind living there 24 hours a day.