The mars rover curiosity has recently found evidence that there was liquid water on the planet’s surface at some point in its history. because we have not found any liquid water on the planet today, what does this imply about mars?

Air masses are characterized by various properties including temperature humidity air pressure and wind speed. which of the following air masses is associated with low relative humidity and high air temperature ?

Which statements about wells are true? check all that apply. a) wells bring groundwater from the unsaturated zone to the surface of the water. b) wells need to be drilled below the water table. c) if water is pumped from a well too quicky, the well may run dry. d) water from wells is generally not safe to drink. e) water gushes from artesian wells due to pressure.

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d