Topic：Some people believe there are intelligent life forms existing on other planets and it is better to send messages to them, but others think it is a bad idea because it is very dangerous to do this. Discuss both views and give your opinion.2016.10.13

开头段：介绍文章背景，人类一直对外星生物是否存在有所怀疑，直到现在，我们的技术水平才能让我们可以尝试去搜寻附近星球上的生命迹象。

The question of whether we are alone in the universe has haunted humanity for centuries, but we may now stand poised on the brink of the answer to that question, as we search for radio signals from other intelligent civilizations. Although groups around the world have been searching intermittently for three decades, it is only now that we have reached the level of technology where we can make a determined attempt to search all nearby stars for any sign of life.（原文化用在这里）

主体段第一段：论述支持向外星生物发送信号的原因1，出于人类最基本的好奇心，人类想要知道我们是不是宇宙中唯一的生命体。

The primary reason for sending messages is basic curiosity - the same curiosity about the natural world that drives all pure science. We want to know whether we are alone in the Universe. We want to know whether life evolves naturally if given the right condition, or whether there is something very special about the Earth to have fostered the variety of life forms that we see around us on the planet.（原文稍作修改，用在这里，作为支持方的第一个论据）

主体段第二段：论述支持向外星生物发送信号的原因2，其他古老文明可以向我们证明，长久的生存是有可能的。他们的存在给我们带来了乐观的理由，也可以将其在应对生存威胁时积累的经验传授给我们，例如如何应对核战争与全球污染带来的威胁，以及如何应对其他我们未发现的潜在威胁。

Additionally, we have had civilization on Earth for perhaps only a few thousand years, and the threats of nuclear war or pollution over the last few decades have told us that our survival may be tenuous. If other civilizations do survive in our galaxy, sending message to them may also give us some cause for optimism and such a civilization will tell us that long-term survival is possible. It is even possible that other the older civilization may send back a reply, passing on the benefits of their experience in dealing with threats to survival, such as nuclear war, global pollution, and other threats that we haven't yet discovered.（原文稍作修改，用在这里，作为支持方的第二个论据）

主体段第三段：论述反对发送信号的原因，会对人类的文化造成冲击，也会将自己星球的安全置于危险之中。

A lot of people do not like the idea of sending messages to aliens "out there". According to their theory, the human race would face the culture shock if faced with a superior and much older civilization. Intelligent species are not willing to co-exist peacefully or harmoniously with other creatures whose civilization apparently lags way behind. （原文用在这里）The main concern is that if other intelligent life forms capture the signals and locate us, they may be powerful enough to invade our planet and destroy or enslave lives on the earth.

结尾段：为到底要不要发送信号这个问题做出适当的总结，人们对此广有争议，但是由于技术的局限性和发送信息用时太久，所以是否要发送信息还要谨慎考虑。

There is considerable debate over whether we should send messages, if we detect the existence of an alien civilization. Everybody agrees that we should not reply immediately. Quite apart from the impracticality of sending a message over such large distances at short notice, it raises a host of ethical questions that would have to be addressed by the global community before any reply could be sent. After all, the stars being searched and hundreds of light years away, so it takes hundreds of years for our message to reach them. It is not important, then, if there is a delay of a few years, or decades, while the human race debates the question of whether to send a message, and perhaps carefully drafts a message.（原文稍作修改，用做结尾段。）