Mars

    Is there life on Mars? We don’t know．We’re sure that people like those on the earth don’t live on Mars．Earth people need oxygen to breathe．There is almost no oxygen on Mars．

    Living on Mars would he like living on a very high mountain．There would be little air. It might be 50 degrees above zero at noon and l00 degrees below zero at night．Many people think there may be plants on Mars．We know that Mars has carbon(碳)．This is a kind of material found in all plants and animals on earth．Through a telescope，Mars looks red．In some places，it seems gray．At times the gray color turns gray—green，then gray again．The gray-green color may be a kind of plant life changing color with the seasons．

  Will men go to Mars one day? If they do，they must take their own oxygen, food and clothing with them．

1．Why can’t people live on Mars? (回答问题)_______________________________

2．Living on Mars would be like living on a very high mountain(改为同义句)

   ________________________________________________________________________

3．The gray．green color may be a kind of plant life changing color with the seasons．(翻译成汉语)这种灰绿色_________________________________________________---

4．They must take their own oxygen，food and clothing with them(改为被动语态)

   Their own oxygen，food，and clothing _________________________________with them．

5．The main idea of the story is that ________________________________on Mars(完成句子)