[填空题]

No one knows exactly why we laugh or why anything that is funny should cause us to make such a peculiar noise. It would be just as logical to stick our thumbs in our ears and wiggle our fingers as it is to giggle or bellow or howl with laughter. But when something strikes our "funny bone", our diaphragm flutters up and down, and we laugh.
66. ______
Stories are among the most popular forms of humor. As a rule, a story is considered inferior if it embarrassed someone, if it makes something sacred appear common, if it makes a person’s weakness the cause for laughter, if it has to have vulgarity to be funny, or if everyone cannot join in the enjoyment of the joke.
People enjoy very much the various situations of humor.
If a man meets a lady on the street, tips his hat to her, and a pigeon flies out from beneath it, most of the people who see it would roar with laughter. This is called the humor of the unexpected happening.

[填空题]Nobody really knows the reason why we sleep.

[单项选择]

No one knows exactly why we sleep. But scientists have learned a lot about how we sleep. From sleep experiments, scientists have learned that there are four different stages of sleep.
When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call this kind of sleep dozing. Scientists call it stage one sleep.
Next, if you are not awakened, you drift into a deeper sleep. Your pulse and breathing become even slower than they were during stage one sleep. But you can still be awakened quite easily. If you take a cat nap, you probably will not get any further than this stage of sleep, which is called stage two.
If you sleep longer than about twenty minutes, you go into the third stage of sleep. Your body is very relaxed. It would take a loud noise to wake you up.
You have probably heard of people who walk in their sleep. No one knows w
A. Reason’s for People’s Sleep
B. Four Stages of Sleep
C. Reasons for Sleepwalking
D. A Sleep Experiment

[单项选择]
No one knows exactly why we sleep. But scientists have learned a lot about how we sleep.
When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call it dozing (打盹). Next, you enter into a deeper sleep. Your pulse (脉搏) and breathing become even slower. But you can still be awakened quite easily. If you take a catnap, you probably will not get any further than this stage (阶段) of sleep. If you sleep longer than about twenty minutes, you get into the third one. Your body is very relaxed. It would take a loud noise to wake you up. You may have heard of people who walk in their sleep. No one knows what makes people sleepwalk. But a person can sleepwalk only during stage four. This is the last and deepest kind of sleep. If someone wakes you up, you might feel very uncomfortable and you need a few minutes to get used to being awake. A
A. two
B. three
C. four
D. five

[单项选择]
No one knows exactly why we sleep. But scientists have learned a lot about how we sleep.
When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call it dozing (打盹). Next, you enter into a deeper sleep. Your pulse (脉搏) and breathing become even slower. But you can still be awakened quite easily. If you take a catnap, you probably will not get any further than this stage (阶段) of sleep. If you sleep longer than about twenty minutes, you get into the third one. Your body is very relaxed. It would take a loud noise to wake you up. You may have heard of people who walk in their sleep. No one knows what makes people sleepwalk. But a person can sleepwalk only during stage four. This is the last and deepest kind of sleep. If someone wakes you up, you might feel very uncomfortable and you need a few minutes to get used to being awak
A. two
B. three
C. four
D. five

[填空题] Why We Laugh
We start finding things laughable — or not laughable — early in life. An infant first smiles at approximately eight days of age. Many psychologists assume this is his first sign of simple pleasure— food, warmth and comfort. At six months or less, the infant laughs to express complex pleasures—such as the light of Mother’s smiling face.
Between the ages of six months and one year, the baby learns to laugh for essentially the same reasons he will laugh throughout his life, says Dr. Jacob Levine, associate professor of psychology at Yale University. Dr. Levine says that people laugh to express mastery over an anxiety. Picture what happens when a father throws his child into the air. The child will probably laugh—but not the first time. In spite of his enjoyment of "flying", he is too anxious to laugh. How does he know Daddy will catch him Once the child realizes he will be caught, he is free to enjoy the ga