71. What would be the best title for the
text?
A. Jesse Owens, A Great American Athlete
B. Golden Moment - A Life?time
Struggle
C. Making A Living As A Sportsman
D. How To Be A Successful Athlete
E
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 eye. 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 sleep?like state where they don’t age. They have now moved on to the
small, non?hibernating mammals (哺乳动物) 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 (监控) 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.