Let's read the conversations and guess the meaning of the following expressions.

Many cultures have different ideas about why people catch colds. For example in the United States, some people think that you can catch a cold if your feet get cold. So, mothers tell small children to wear warm boots in the winter. In other places, including parts of the Middle East, some people believe that strong winds cause colds. So, on trains and buses, people usually don't like to sit next to open windows. In parts of Europe, some people think that wearing wet clothes will give you a cold. They say that after you go swimming, you should quickly put on dry clothes. Today, scientists know that colds are caused by a virus（病毒）. But the old ideas are still very strong, and many people still follow them to avoid（避免）getting ill.

    In Europe, small cars have always been more popular than large cars. In the United States, large cars and midsize cars are more popular than smaller cars. As a result, European automakers used to make different kinds of small cars while American automakers used to build bigger, heavier cars. However, these days, automakers in both America and Europe produce cars of different sizes. This is because most automakers export their cars all over the world.

    The price of gasoline (汽油)is one reason for differences in car choices. Since gasoline is more expensive in Europe, many Europeans want smaller, lighter cars that will travel a long way on a gallon（加仑）of gasoline.

    Other reasons also enter into the big or little car decision. Many European cities have narrow, winding（弯曲的） streets. In these cities a small car is easier to control than a large one.

    For a long time, few Americans bought small cars. Instead they chose large cars, because these roomy cars were more comfortable for large families and long trips. Some people also liked the powerful engines（发动机） that large cars had. Since gasoline was cheap, drivers did not mind that the large cars used a lot of gasoline.

    But in the 1970s, there were gasoline shortages in the United States. The price of gasoline went up. Though large cars were still more popular than smaller cars, sales of small cars increased. Some people also bought small cars because these cars caused less air pollution than larger cars.

    Today, Americans' car preferences are still changing. Though Americans are still buying many small cars, the fastest growing sales are for certain kinds of large cars. These types of cars are called minivans and sport utility vehicles(SUV). They are very popular today. But of course, that could change tomorrow.

    An important question about eating out is who pays for the meal. If a friend of yours asks you to have lunch with him, you may say something like this, "I'm afraid it'll have to be someplace cheap, as I have very little money." The other person may say, "OK, I'll meet you at McDonald's."

    This means that the two agree to go Dutch, that is, each person pays for himself. He may also say, "Oh, no. I want to take you to lunch at Smith's," or "I want you to try the Chinese dumplings there.

    They're great." This means the person wants to pay for both of you. If you feel friendly towards this person, you can go with him and you needn't pay for the meal. You may just say, "Thank you. That would be very nice."

    American customs about who pays for dates are much the same as in other parts of the world.

    In the old days, American women wanted men to pay for all the meals. But, today, a university girl or a woman in business world will usually pay her bill during the date. If a man asks her for a dance outside the working hours, it means "Come, as my guest." So as you can see, it is a polite thing to make the question clear at the very beginning.