Why is it difficult to find evidence of life on other planets

Due to limited knowledge and strength to explore the universe

Explanation:

As an human being our potential is limited to only accessing the things which we can see or imagine or about which we have studied in our schools and colleges

Apart from life forms on planet earth,  humans are not aware of any other life form on any other planet. Nor they have any idea whether the life form on other planets will have the same characteristic as that of life forms on earth or it may be exceptionally a different scenario.

We have not yet explored universe beyond our solar system and hence we have very very limited knowledge scope.

Thus, it is difficult to find evidence of life on other planets

hello there are no statements below!

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.