1 . Is there a way to turn back the aging process in people? For centuries, people have been looking for a “fountain of youth.” The idea is that if you find a magical fountain, and drink its water, you will not age.

Researchers in New York did not find an actual fountain of youth, but they may have found a way to turn back the aging process. It appears that the answer may be called the hypothalamus, which is part of your brain. It controls important body activities, including growth, the way we process food and so on. Researchers found that hypothalamus neural stem cells (干细胞) also influence how fast aging takes place.

Dongsheng Cai was the leading researcher in a study on aging in mice. He and his team reported their findings. “when the hypothalamus starts aging, particularly the loss of hypothalamus stem cells, so does the body.” he said.

Using this information, the researchers began trying to activate (激活) the hypothalamus in laboratory mice. The results show that the treatment slowed aging in the animals. “When we injected the hypothalamus stem cells to the middle-aged mice, the mice aged slowly and they could also live longer.”

But these results were just from studying mice in a laboratory. If the mice can live longer, does that mean people could have longer lives? The next step is to see if the anti-aging effects also work in human beings. If so, they say the findings could lead to new ways to help doctors identify and treat age-related health problems.

1. Why does the author mention the “fountain of youth” in the first paragraph?

A．To explain what the “fountain of youth” is.

B．To introduce the hypothalamus.

C．To show how to find the “fountain of youth”.

D．To help people find the “fountain of youth”.

2. What does the underlined word “it” in Paragraph 2 refer to?

A．The brain.	B．The aging process.
C．Hypothalamus.	D．The stem cell

3. What do we know about the study done by Cai?

A．They have found a way to turn back the aging process.

B．The brain controls growth, reproduction and the way we process food.

C．The decrease of hypothalamus stem cells can lead to aging.

D．The finding has been applied to human beings.

4. Which of the following can be the best title of the passage?

A．The Secret of Youth

B．A New Discovery about Aging

C．The Ways of Slowing Down Aging

D．Hypothalamus — the Fountain of Youth