Travelers from Earth to Mars would have to endure low levels of gravity for long periods of time, avoiding large doses of radiation, plus contending with the chemically reactive Martian soil, and perhaps even ward off contamination by Martian life-forms.
-
AMars would have to endure low levels of gravity for long periods of time, avoiding large doses of radiation, plus contending
分析该选项
-
BMars would have to endure low levels of gravity for long periods of time, avoid large doses of radiation, contend
分析该选项
-
CMars, having to endure low levels of gravity for long periods of time, would also have to avoid large doses of radiation, plus contending
分析该选项
-
DMars, having to endure low levels of gravity for long periods of time, avoid large doses of radiation, plus contend
分析该选项
-
EMars, who would have to endure low levels of gravity for long periods of time avoid large doses of radiation, contend with
分析该选项