Unit 3 Back to the past 单元达标检测（教师用书word）-2022-2023学年新教材高中英语选择性必修第三册【精讲精练】译林版

[本卷满分120分，考试用时100分钟] 第一部分　阅读(共两节，满分50分) 第一节(共15小题；每小题2.5分，满分37.5分) 阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。 A Today, 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 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. Mars has fascinated people since ancient times. Since the 1960s, we have been sending unmanned spacecraft to Mars. Our probes (探测器) have orbited the planet, sending back valuable data and stunning images. Our robots have explored the Martian surface, testing the soil and searching for resources, water and signs of life. Encouraged by discoveries over the year, space agencies of various countries are panning manned missions to Mars that could take place within the next 25 years. No doubt that humankind is drawn towards Mars, with dreams of making it our second home. However, sending people there will require all the skill, courage and intelligence of the human race. While the Moon can be reached within days, it would take months to reach Mars, travelling through dangerous solar radiation (辐射). 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. Although the two­year experiment was not a success, it did provide us with a better understanding of how humans might be able to live on another planet. More recently, scientists have succeeded in growing a variety of plants in an environment similar to that on Mars. That definitely is a big step forward. For now, human settlement of Mars is still decades away. Until we are finally able to live on another planet, we need to take much better care of our own. Right now, it's