1、语法填空Plan B: Life on Mars？In 1._ 1960s and 1970s，the greatest fear was that the human race，and possibly all advanced life forms on the planet，could 2._(wipe) outby nuclear missiles，just at the push of a button.Today，however，environmental problems have taken over3. _ the greatest risk to life on Earth
2、.Scientists are thinking of ways 4._(lower) this risk，such as replacing coal and oil with forms of renewable energy. 5. _ they are also preparing for the worst: 6. _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 optio
3、n is 7. _( explore) other planets to see if we could live on them.The most likely 8. _(choose) is Mars，which is relatively close 9._Earth and has an environment less hostile than 10 _ of other planets.Mars has fascinated people since ancient times，and today our interest 11._ Martian exploration is g
4、reater than ever before.Films such as The Martian enjoy worldwide 12._(popular) .More governments and organisations are making efforts 13._(educate) the public on the Red Planet，for example，the Mars Desert Research Station in the Utah desert of the US and the Mars Village in Northwest Chinas Qinghai
5、 Province.Since the 1960s，we 14._(send) unmanned spacecraft to Mars.Our probes have orbited the planet，15._(send) back valuable data and stunning images.Our robots have explored the Martian surface，16_(test) the soil and 17._(search) for resources，water and signs of life. 18._(encourage) by discover
6、ies over the years，space agencies of various countries are planning manned missions to Mars 19._ could take place within the next 25 years.There is no doubt 20._ humankind is drawn towards Mars，21._ dreams of making it our second home.22._，sending people there will require all the skill，courage and
7、intelligence of the human race.While the Moon can 23._(reach) within days，it would take months24. _(reach) Mars，travelling through dangerous solar radiation.And even if the first settlers do reach Mars safely，they may not be able to return25._ Earthever. 26._(stay) alive will be a daily challenge，bu
8、t as 27._(prove) by the Biosphere 2 experiment，not impossible.As early as the 1980s，scientists were building Biosphere 2 in the Arizona desert.It consisted of a closed space 28._ people，animals and plants could live together.The “closed” concept meant that the space was designed 29._(function) with
9、its own oxygen，food and water，30._(need) nothing from the outside world. 31._ the twoyear experiment was not a success，it did provide us with 32._ better understanding of 33._ humans might be able to live on another planet. More recently，scientists have succeeded 34._(grow) a variety of plants in an
10、 environment similar 35._ that on Mars.That definitely is a big step forward.For now，human settlement of Mars is still decades away.In the meantime，scientific research shows that the planet Earth is getting warmer.This change is 36._(cause) by human activity and is having a terrible effect 37._ the
11、biosphere.Until we are 38._(final) able to live on another planet，we need to take much 39._(good) care of our own.Right now，its the only one we have！重点词汇Mars n火星 advanced adj.高级的；先进的 wipe v擦，拭，揩 wipe out 彻底摧毁，消灭nuclear adj.核武器的 missile n导弹 take over 接管；接替 renewable adj.可再生的；可更新的 terrifying adj.极其可怕的
12、，骇人听闻的 relatively adv.相当地；相对地hostile adj.(生长环境)恶劣的 popularity n普及，流行；受大众欢迎 make efforts to do.努力做 unmanned adj.无人驾驶(操纵)的 spacecraft n航天器，宇宙飞船 probe n航天探测器 orbit v环绕运行 stunning adj.极具吸引力的；令人惊奇的 agency n机构；(尤指政府内的)局，部，处 mission n任务 solar adj.太阳的；日光的 radiation n辐射 consist v由组成 consist of 由构成，由组成 concep
13、t n观念，概念 function vi.起作用；正常工作；运转 n作用；功能 a variety of 各种各样的 be similar to 与相似 definitely adv.清楚地，明确地，肯定地 in the meantime 在此期间，与此同时 have an effect on 对有影响 biosphere n生物圈 take care of 照顾；负责 参考答案1.The 2.be wiped 3.as 4.to lower 5.But 6.what 7.to explore 8.choice 9.to 10.that 11.in 12.popularity 13.to educate 14. have been sending 15sending 16.testing 17.searching 18.Encouraged 19.that 20.that 21.with 22.However 23.be reached 24to reach 25.to 26.Staying 27.proved 28.in which 29.to function 30.needing ,31.Although 32.a 33.how 34.in growing 35.to 36.on 37.being caused ,38 finally,39.better4/4
