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D. by telling stories
Moving to Mars
When:
Why:
by the year 2100
crowded
polluted
Para1
Para1
The population is increasing quickly.
Mars will turn into another Earth in the future.
Moving to Mars
When:
Why:
What
(life)
How:
by the year 2100
crowded
polluted
in spacecraft
Para1
Para1
Para2
months
about 20 minutes
very slow
at the speed of light
Moving to Mars
When: