7) Today's rockets require huge amounts of 2fossil fuel.
However, the space elevator is
is energy saving and
eco-friendly. The space elevator may use a lot of electricity
when it goes up, but it can also produce electricity when it
comes down. That electricity can be stored in a battery and
used when the elevator goes up again. The cost of a single
trip may be about a hundred times lower than that of a trip
on a rocket. Unlike rockets, the space elevator will not
produce any 4carbon dioxide.
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large, small, huge t
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2. fossil fuel [ hete t
3. that the (
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4. carbon dioxide [=
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