Error Correction (15 minutes)
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Some people, in all seriousness, say that
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% M, `" c9 }$ U# i7 Q humans will be living in space within the next7 p: M+ Y8 d5 f
- K4 Q F6 B0 q4 ?- ] hundred or so years. Planet Earth will be crowded,5 ^* j# u# j: q9 b% M3 b5 f
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dirty and lack of resources. A sort of exodus --71.' }$ n3 p! g, U, s; h! F. J8 m
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(移居) of mankind will begin.
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Spaceships will be assembled so that they$ n! B& j" U, E9 Q* r8 i+ R
! u8 `4 H7 [. t revolve around the earth. Some may orbit around
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. l: a6 k8 d4 ?& c& W Mars. These space stations will be serviced by1 ^: z7 \6 h( k/ r: }
: t$ f) u: p7 B7 X3 Q+ } space buses. We saw the first space bus launch in --72.
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' J5 D+ ]* H+ ~: ]* d April 1981. This was "Columbia", it made several --73.
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5 e# D4 G5 P$ v6 [# ] orbits around the earth and then returned, landing2 Z9 y% u( ~' X: [
( k( n& D- l# Y on a huge dry lake bed in California. "Columbia"
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2 V7 U# E7 Q9 |6 R1 s0 g) ? will be used again. previous spaceships have$ z7 A2 _2 O. w/ m
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been abandoned, only the nose cone being used
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8 i3 y/ H y+ l to bring the crews back to earth. --74.
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Upon established, each space station will --75.& X7 j; n8 Y1 ^1 Y: D( V, X# O3 X! |
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generate its own atmosphere and have its own. d. ~- V$ j5 t' h
8 G. [; [# Z) e( q2 g; J: w( Z! f agriculture. it will need to rotation to provide --76.
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# @9 F- M" a& S- w) K& p0 D an artificial gravity; people will be forced inwards --77.
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. e0 L" N/ E! J+ i" b, s, f from the center by centrifugal（向心的）force. [" h. d6 P0 u3 N; L5 y
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The moon and Mars could become new sources of
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new materials. Driving through space will no --78.
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longer need Earth fuel-the energy would come
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from the sun. This energy would be converted from --79.
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) J. M! @9 Z2 n# W6 ~9 v electricity to work magnetic rockets.
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& |+ u) A. p/ b# K& e' } That all sounds quiet fantastically but, with --80., n R% ~: q3 g& Y) b- J2 ]
, ^) _# E; X$ _* _ the rapid development of modern technology, who
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+ T6 v4 g; c1 m. I knows about what the future holds? |
发表于 2012-8-14 10:46:58
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