题目内容：

Have you ever dreamed of visiting a planet in the Milky Way (银河系)? While the trip sounds exciting, it would take years and years to reach your destination. So in the future, bedtime for astronauts may be more than a few hours of regular shut eyes. They would have to sleep for years.

European researchers are now conducting hibernation experiments. The study may help them understand whether humans could ever sleep through the years it would take for a spaceflight to distant planets. "If there was an effective technology, it could make deep space travel a reality," said Mark Ayre of the European Space Agency last month.

What seems like a science fiction is not completely unlikely. Researchers have been able to use chemicals to put living cells into a sleeplike state where they don’t age. They have now moved on to the small, non hibernating mammals like rats.

A major challenge is the fact that cells can be very simple systems, whereas body organs are far more complex. "It’s like moving from a simple Apple computer to a supercomputer," said Marco Biggiogera, a hibernation researcher at Italy’s University of Pavia. Just like bears and frogs, the hibernation of human beings would cause a person’s metabolism (新陈代谢) to lower so they would need less energy.

Medical research, however, is just half of a spaceflight hibernation system. There is a challenge of designing a suitable protective shelter. Such a shelter would provide the proper environment for hibernation, such as the proper temperature. It would also have to monitor life functions and serve the physiological needs of the hibernator.

According to Ayre, the six person Human Outer Planets Exploration Mission (使命) to Jupiter’s moon (木星的卫星) Callisto, could be an opportunity to use human hibernation. The mission aims to send six persons on a five year flight to Callisto, where they will spend 30 days, in 2045.

1.According to the article, the hibernation research _______.

A. is just an idea

B. is always a science fiction

C. has already finished successfully

D. has made some progress

2.In a hibernating state, a person needs ________.

A. less sleep  B. more food

C. less energy   D. more movement

3.The first try of the hibernation technology       the six person Human Outer Planets Exploration Mission to Jupiter’s moon Callisto.

A. will be                 B. has been planned for

C. is certain to be        D. may be

4.What is the best title of the article?

A. Hibernation study for space travel

B. Welcome to our space travel

C. To hibernate, to live longer

D. Welcome to the Milky Way