不需要的，例如A change in Mars' climate may have killed off primitive life forms early in the planet's history. If so, we may find fossilised evidence of life on Mars. Only time will tell.
上面是英国BBC网站上的一个句子，见
http://www.bbc.co.uk/science/space/life/looking/mars.shtml
要加 因为火星是独一无二的 比如 the earth，the moon
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024