The first chemicals formed on the earth were ………………. etc.
A. oxygen, CFC, ozone
B. DNA. RNA and nucleotides
C. salt, sugar, proteins
D. water, ammonia, methane
Answer:D
The first chemicals formed on the earth were ………………. etc.
A. oxygen, CFC, ozone B. DNA. RNA and nucleotides C. salt, sugar, proteins D. water, ammonia, methane