英语周报网八年级

In the greatest fear was that the human race 进入查看：2022-2023学年英语周报八年级第16期答案及试题 以下内容仅作展示，图片上方文字进入查看。 In the 1960s and 1970s, the greatest fear was that the human race, and possibly all advanced life forms on the planet, could be wiped out by nuclear missiles. Today, however, environmental problems have taken over as the greatest risk to life on .Earth. Scientists are thinking of ways to lower this risk, such as replacing coal and oil with forms of renewable energy. But they are also preparing for the worst: what can we do if the terrifying scenes in films such as The Day After Tomorrow  happen in real life? What is our plan B for Earth? One option is to explore other planets to see if we could live on them. The most likely choice is Mars, which is relatively close to Earth and has an environment less hostile than that of other planets. Mars has fascinated people since ancient times, and today our interest in Martian exploration is greater than ever before. Besides, more governments are making efforts to educate the public on the Red Planet. There is no doubt that humankind is drawn towards Mars. However, sending people there will require all the skill, courage and intelligence. While the Moon can be reached within days, it would take months to reach Mars, travelling through dangerous solar radiation. And even if the first settlers do reach Mars safely, they may not be able to return to Earth — ever. Staying alive will be a daily challenge, but as proved by the Biosphere 2 experiment, not impossible. As early as the 1980s, scientists were building Biosphere 2 in the Arizona desert, consisting of a closed space in which people, animals and plants could live together. Although the two-year experiment was not a success, it did provide us with a better understanding of how humans might be able to live on another planet.