Which of these is an example of water pollution? a. a clear/cut forest
b. an eroded hillside
c. arid land
d. agricultural runoff

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes