Radiation is a concern with travelling away from the Earth. What kind of radiation is concerning to astronauts in this journey? ( the trip to Mars)
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[fw.02]sinkholes are often formed as a result of the actions of. a.heat on recharge b.pressure on aquifers c.acid in groundwater d.minerals in hot springs

Lines of longitude are like stripes from the top of the globe down to the bottom virtually slicing the earth like an orange

Can someone me with this plz? ! i'm putting 20 points on it!