题目内容：

    As the weather gets warmer, there are few things that are better to do than travel. But traveling might not be that fun for everyone, especially for those who have motion sickness(晕动症).

Motion sickness is also called travel sickness. It is a common experience for many people. Depending on how you travel, it can be called carsickness or seasickness. People with motion sickness feel very uncomfortable while they are in motion. They feel sick and dizzy(眩晕的), like the room around them won't stop turning.

It is generally believed that motion sickness happens when your senses become confused with each other, Scientific American reported.

We use different parts of our body to sense movement. Our eyes tell us if we are moving. The inner ears(内耳) contain a special liquid（液体）that helps us sense our direction and balance. Our muscles（肌肉）react to movement.

When you move around, these body parts work well together. But when you are in a car or an airplane, they get confused. Your inner ear gives off the information that you’re moving, but your eyes say you’re sitting still because you can’t see that you’re moving. This mismatch(不适配) gives us motion sickness.

But some people are less sensitive to motion sickness. This may be because they have certain genes(基因) that prevent mismatching senses, Bethann Hromatka, a genetics expert from the US, told the Atlantic.

Although there are many ways to deal with motion sickness, scientists believe that the key is to simply try to get used to it. For example, some astronauts do special exercises that give them mild(轻微的) motion sickness. After a week or two, the astronauts become used to it and don’t feel uncomfortable anymore, Sam Puma, a NASA flight doctor, told the BBC.

1.What do we know about motion sickness?

A.It is called carsickness when you travel by car.

B.It happens to only a small number of people.

C.It can make traveling more fun.

D.It causes the room to turn continuously.

2.How do people feel if they have motion sickness?

A.Worried and angry. B.Sick and dizzy. C.Thirsty. D.Sleepy.

3.Why do some people have motion sickness?

A.Because their senses stop working.

B.Because they lose their sense of direction.

C.Because their eyes can't see properly.

D.Because there is a mismatch among their senses.

4.The astronauts are mentioned to show that ______.

A.it is impossible for others to deal with motion sickness

B.astronauts can easily get used to motion sickness

C.special exercises can help deal with motion sickness

D.motion sickness has something to do with genes