The symbol on a weather map for a cold front is what? A. a line with triangles on it
B. a line with semi-circles on it
C. a line with squares on it

How many species of living things are alive on earth today? more than 1,000,000 none of these answers are correct 100-500 1,000 –500,000 o 500,000 -1,000,000

What best explains the inability for life to exist in earth early atmosphere

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