Answer: Deep ocean currents are affected by temperature but not by salinity.
Explanation: I think it's this because I know it takes a while for deep ocean currents to move so it isn't the first one.
There are 4 electrons altogether shared between carbon atoms in a molecule of C2H4, to be more precise there are 2 electron pairs shared between the carbon atoms.
If this is for the scientific process unit, the answer is passing laws to prevent certain types of scientific research. I know because I had this question in biology.