Help is you can plz 囧rz

the one under the sun is evaporation

the clouds are condensation

the last one is persipastion  

and for B it does not get saltier because the salt doesn't evaporate with the water

Explanation:

answer; /// the answer to the first question is (b) it began when people first deliberately seeds; /// and (d); // it gave people a steady food supple for the first time;