During a storm, you hear a clap of thunder. What is the medium of the sound wave that traveled to your ear? A. Clouds
B. Air
C. Light
D. Rain

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