根据短文内容，从短文后的七个选项中填入空白处的最佳选项。选项中有两项为多余选项。

                                                                What is a dream?

     For centuries, people have wondered about the strange places that they seem to visit in their sleep.

51._____ However, they have been valued as necessary to a person's health and happiness. Historically

people thought dreams contained messages from God. It was only in the twentieth century that people

started to study dreams scientifically believing that they tell about a person's character. 2._____ He

believed that dreams allow a person to express fantasies or fears,which would be socially unacceptable

in real life.

     The second theory to become popular was Carl Jung's compensation theory. Jung, a former student

of Freud, said that the purpose of a dream is not to hide something, but rather to communicate it to the

dreamer. 3. _____ Thus, people who think too highly of themselves may dream about falling; those who

think too little of themselves dream of being heroes.

     Using more recent research, William Domhoff from the University of California found that dreaming

is a mental skill that needs time to develop in humans. 4._____ Until they reach age five, they can not

express very well what their dreams are about. Once people become adults, there is little or no change in

their dreams. The dreams of men and women differ. For instance, the characters that appear in the dreams

of men are often other men, and often involve physical aggression.

     The meaning of dreams continues to be difficult to understand. 5._____ If you dream that a loved one

is going to die, do not panic. The dream may have meaning, but it does not mean that your loved one is

going to die.

A. Dreams make up for what is lacking in waking life.

B. However, people should not take their dreams as reality.

C. They have been considered as meaningless nighttime journeys.

D. It gives scientists chances to understand human mind better.

E. Children do not dream as much as adults.

F. They think their mind is trying to tell them something.

G. First, there was Sigmund Freud's theory.