Without the earth’s atmosphere to protect them, astronauts can be exposed to intense radiation from the sun, ____ them at risk of cancer.
A.to leave | B.leaving | C.having left | D.left |
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Without the earth’s atmosphere to protect them, astronauts can be exposed to intense radiation from the sun, ____ them at risk of cancer.
A.to leave | B.leaving | C.having left | D.left |