People try to conserve some resources, like fossil fuels, because they are not replaceable. Why can't these resources be replaced?
A. They must be transported long distances
B. Processes to make them take longer than a human's lifetime
C. No one can afford to buy more of them
D. It is impossible to extract more from the Earth

B. processes to make them take longer than a human's lifetime

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.

your spelling is a little off : ]