Change active sentences to the passive and passive sentences to the active.
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| 1 |  |  The United States could launch space stations. |
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| 2 |  |  Space colonies should be started by teams of scientists. |
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| 3 |  |  Our scientists will perfect the necessary technology soon. |
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| 4 |  |  Someday all life might be destroyed by our sun. |
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| 5 |  |  Life on some planets will be frozen by the extreme cold. |
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| 6 |  |  The expanding sun might consume Venus. |
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