21.   If life did exist on other planets, Wyatt said, it would most likely be found on a terrestrial planet like the Earth.

22.   If microbial life does exist on the planet, the organisms may make the astronauts sick and be brought back by them, contaminating Earth.

23.   IN COSMIC news, scientists last week discovered evidence of water on Mars, raising the possibility that life could exist there.

24.   It is also too cold, it would seem, for any life to exist.

25.   It is like a time capsule where life exists as it once did everywhere but which vanished long ago in the modern world.

26.   It will also look for subsurface water, which may aid in understanding whether life could once have existed there.

27.   Just as he protected the cave, she said, he wanted to establish safeguards to protect whatever life might exist on Europa from damage by spacecraft.

28.   Life existed in a thin, Earth-girdling envelope of air and water, the so-called biosphere, and that was that.

29.   Life does exist without football, as hard as that may be to believe.

30.   Life here cannot exist without trees, he explained.