1 . Tears well up in people's eyes for a lot of reasons. A teardrop running down the cheek is the ultimate symbol of sadness, but people may also cry because they just cut an onion, or maybe they're trying to blink out an eyelash.

For the most part, tears help maintain healthy eyes. When you blink, basal (基底的) tears clean and smooth the eyes, which helps you to see clearly, according to the American Academy of Ophthalmology. Moreover, reflex (反射性的) tears, or those that happen unconsciously, help clear the eyes of irritants (刺激物), including dust and the gas that's produced when a knife slices a raw onion, said Andre Silva, a doctoral student of psychology at the University of Minho in Portugal.

Emotions can also bring about tears in humans. These emotional tears can serve as a means of nonverbal communication. Silva said, “Babies cry to signal to their mothers that something's up. It's a pure attention call. Some people think that babies are capable of controlling adults by crying, but that idea is false and misleading, as a baby is not conscious of being tricky: In a way, we can consider these tears as being somewhere between basal tears and emotional tears.”

As people grow older, they begin to use their tears to express emotions, such as happiness or sadness. These tears may promote compassion and empathy in others. But beware of people who may use their tears to control others. “Some sensitive people may be easily controlled through the crying of others, and may easily shed tears that can also be used by others to control them,” he said.

So, emotional tears have both advantages and disadvantages. “They are a powerful communication device and a powerful manipulative (操纵别人的) device,” Silva said. Crying also makes it hard for some people to mask their feelings when they're in the middle of an extreme emotional state.

1. What's the function of reflex tears?

A．Reflecting our feelings.

B．Being used to affect others.

C．Serving as a means of interaction.

D．Clearing away harmful matters in the eyes.

2. What may Silva agree with according to the text?

A．Tears are usually used to pity others.

B．Babies burst into tears without tricks.

C．People mask their feelings when crying.

D．Blinking out an eyelash makes it easy to cry.

3. What can be learned from the text?

A．We ought to identify tears.

B．We should control babies, crying.

C．We need to smooth our eyes by emotional tears.

D．We can hardly fan others' sympathy by tears.

4. Which of the following can be the best title for the text?

A．Why do people cry?

B．Why can tears control others?

C．How do people express emotions?

D．How can people make use of tears?