- 2018年04月11日13:05 来源：小站整理
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A trip to mars would definitely be challenging but scientists have proposed solutions to the problems the reading selection discusses.
First of all, food, water and oxygen. Well astronauts can use hydroponics. Hydroponics is a technique for growing plants with their roots in water rather than in soil. It requires relatively little space. Using hydroponics, the astronauts should be able to cultivate food crops in the spacecraft. In addition, the hydroponic will grow plants with recycle waste water and release it as clean water vapor, which can be collected as drinking water. And of course, all plants absorb carbon dioxide and release oxygen. So thanks to hydroponics the astronauts will also have fresh air to breathe.
Second, the effects of zero gravity. Over the last few decades, we have launched several space stations orbiting the earth. And a number of astronauts have spent many months on them in a zero gravity environment. These astronauts have learned to use several techniques to safely manage the effects of zero gravity. For example, regular exercise prevents the decrease in muscle mass. Likewise, taking vitamins and minerals like calcium slows down the decrease in astronauts’ bone density.
Third, solar radiation. Astronauts traveling to mars will be exposed to some solar radiation but this radiation will not be at dangerous levels all the time. The sun only releases dangerous amounts of radiation occasionally, during periods when it is particularly active. In order to avoid this threat, the spacecraft could be equipped with special instruments that monitor solar radiation and with a small shelter that shield against radiation but doesn’t add much weight to the ship. Most of the time, the astronauts will go about their normal business in unshielded areas of the spacecraft. But when their instruments detect increased radiation, they could stay in the small shielded area until the danger has passed.
Both the reading and listening are arguing over a question whether it is possible to send human being to Mars. The reading lists out three problems to a successful carrying out. However, the listening offers three solutions to these questions.
First, the reading raises the question that it takes too long to send people to Mars, approximately two years and no spacecraft could take that many loads of food, water and life essentials. Instead, the listening says this is not a real problem since the astronauts could use hydroponics to grow crop plants in water and food will not be an obstacle. Also, they could grow plants with recycle waste water and reuse it as clean water vapor, which could be drunk. Plus, since all plants do photosynthesis, the astronauts could breathe fresh air released by them.
Second, the reading asserts that living in a zero gravity environment would exert a negative effect on one’s health. Nevertheless, the professor says that the astronauts have learned to use several techniques to make up for the health issue. They will do regular exercise to prevent muscle mass decrease and take vitamins and minerals to slow down problem with their bone density. In another word, they’ve figured out how to cope with the potential health problem.
Third, the reading claims that radiation emitted by the sun would be dangerous to astronauts. This time professor subtly rejects by pointing out that a third solution has come out. The spaceship would be equipped with a special instrument to monitor the radiation. What’s more, the device could also shield against the radiation. When astronauts meet the period of a large amount of radiation, they could hide behind the shielded areas and come out when the danger has passed.