There may be life on Mars(火星). We know1 about Mars than about any other planet （行星）. But astronomers are still guessing about many things.2 example, we think that on Mars 3 may be changes of weather during the year. Our own weather 4 from winter to summer. Perhaps it is the same on Mars. In Mars' mid-summer we can see brown places on the planet. In mid-winter these places are white.5 some scientists believe that plants grow on Mars during mid-summer and change color in winter. They do not 6 that there are green fields on Mars. But perhaps there is some kind of life.
