阅读理解
Mark Twain once said that everyone talked about the weather, but no one ever did anything about it. This was true in his day. But it may not be the case in today's world. In fact, humans have found many different ways to control the weather.
Cloud seeding(云催化) is a kind of technology that can control rain. It is done by spreading chemicals like dry ice or silver iodide(碘化银) inside of clouds, either by rocket or airplane. Thus it change the amount of water inside the clouds, which helps to control the amount of rain, the time when it rains and even where it rains.
This technology has helped to solve drought. It has also played a key role during important events. For example, China used cloud seeding in Beijing just before the 2008 Olympic Games in order to stop rain from falling during the event.
However, scientists are still debating how to use this technology. On the one hand, it is believed that it might haveside effects. For example, silver iodide may be bad for the environment. On the other hand, no two clouds are the same, so every new experiment introduces new conditions.
Using lasers(激光) to change the weather has been tested in a lab, and it has been very successful on a small scale. Scientists are still trying to figure out how to use it in the real world, but it could be a new way to stop climatic change.
In addition to controlling rain, scientists have also tried to find ways to weaken storms and hurricanes. Scientists at the US National Hurricane Centre Headquarters think it might be possible to control hurricanes by using lasers. Others believe that burning petroleum in a hurricane's path could slow storms down.
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