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tpo-52
tpo-52 - Writing - question1
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   Asteroids are large space objects made of rock and ice. There are hundreds of thousands of asteroids in our solar system. Though we often hear ideas about establishing colonies of humans to live and work on our Moon or our neighboring planet, Mars, some think that sending people to an asteroid would actually be the best colonization option for a number of reasons Low Gravity To begin with, asteroids are often much smaller than planets, so they have lower gravity.

   When landing a spaceship, the craft would not be pulled as strongly or as forcefully toward the asteroid's surface, making the landing safer than landing on the Moon or Mars; it would also allow a spacecraft to carry much more equipment needed to set up the colony. It would also be easier for the spacecraft to take off again, so the spaceship would need to carry considerably less fuel for the trip back to Earth. Mining Valuable Metals Next some asteroids are rich in valuable elements and precious metals that are relatively rare on Earth, such as gold and platinum. An asteroid colony would be extremely profitable and a good source of these raw materials. The colonists or businesses sponsoring them could more than pay for the cost of their support by mining minerals and sending them back to Earth. Easy to Reach Finally, asteroids are a good option for colonization because some of them would be very easy to reach.

   There are a number of asteroids that periodically come within or near Earth's orbit Some of them actually get closer to Earth than our Moon. So these asteroids would be much easier and more affordable to get to and get back from than a planet like Mars, which would require a two-year trip in each direction.

   In the reading, the article comes up with an assumption that sending people to an asteroid would be the best colonization option and lists out three reasons to support this statement. However, in the listening, the professor questions the feasibility of this plan and offers his own perspective on the issue. 

  First, the reading states that the low-gravity environment on asteroids makes it convenient for people to colonize there. However, in the listening, the professor presents certain risks of low-gravity environments and points out the problem is not that simple. People who live in a low-gravity environment would suffer from muscle loss and lower bone density. Even those astronauts who just spend a short period of time in spaceship would also have muscle and bone density loss, not to mention stay in a low-environment asteroid for longer periods. Second, the reading claims that the abundant resources on asteroids, such as gold and platinum, would make the prospect of the colonization very profitable and is worth colonizing.

   However, in the listening, the professor also points out one potential problem in it. The costs of mining and transporting these materials back to earth would be so high that the profit could be quite minimal. Also, if these raw materials are excavated in large quantities, the price of them is likely to be low in the market because there are too many of them. In this case, the whole business is not lucrative at all. Third, an easy reach to an asteroid is the third reason why it is worthy of colonization. In the listening, the professor points out one exception which will make the whole issue more complicated than it was expected.

   Asteroids are easy to reach but not that easy to return from. When an asteroid comes near to the Earth, it is indeed convenient to get onto it. But some orbital paths of asteroids are not predictable, they could get quite far away from the Earth. Under this circumstance, getting back from there would be a challenge, or even an illusion. Therefore, in the listening, the professor asserts that the asteroid colonization is not as simple as it was expected by pointing out three potential problems in the plan.

 

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题目: Summarise the points made in the lecture, being sure to explain how they cast doubt on specific points made in the reading passage.
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