B
With low temperatures and less and less food, winter is an uncomfortable season for animals. Many animals enter hibernation to get through it.
Hibernation is when an animal goes into a state of being inactive for a long time. Animals hide away from their enemies. Hibernation makes the animals' bodies cool and slows their heartbeat to just a few times per minute, for up to months at a time.
But why don't humans hibernate? Humans don't enter hibernation for many reasons. Our body is not designed for hibernation. Our ancestors were animals with no history of hibernating. For example, human waste is a huge problem for human hibernation. Animals are able to stop their waste. Unluckily, humans can't do this.
There are other problems. Body temperatures below 28°C may bring a lot of trouble and cause ache. Low temperatures can also make people easier to be ill. In fact, humans don't need to sleep through winter. We have found fire, clothes, shelter, hunting and farming. These ways can help us keep away from the cold.
Could humans hibernate in the future? For long-distance space travel, it's possible. A journey to Mars would take around months at the moment. If we hope to visit another star system, even if we could travel at the speed of light, the journey would take years. Being able to hibernate would make such distances less boring for the astronauts and save energy.
Some scientists have treated that seriously. They started to do something on long-term hibernation as a way to make long-term space travel possible and easier.
(
C
) 6. Why DON'T humans hibernate?
A. We have lots of food to eat.
B. Humans don't like sleeping.
C. Our body is not designed for hibernation.
D. The temperature isn't low enough.
(
C
) 7. Which of the following is TRUE according to the passage?
A. Humans can't keep away from the cold.
B. All the animals enter hibernation to get through winter.
C. Human hibernation is helpful for long-term space travel.
D. Hibernation makes animals' bodies warm and their heartbeat fast.
(
C
) 8. What does the underlined word "that" in the last paragraph refer to?
A. Long-distance space travel. B. A journey to Mars.
C. Human hibernation in the future. D. The astronauts and energy.
(
A
) 9. What's the best title for the passage?
A. Is human hibernation possible?
B. Is human hibernation easy?
C. Is human hibernation interesting?
D. Is human hibernation different?
