Respiratory structures of land animals can include which of the following: a. lungs b. skin c. gills d. both a and b

Option D

Explanation:

Animals on land get air directly from atmosphere. They need to extract it from any other sources like water animals use air dissolved in water or so.   Lungs is the most prominent and essential organ of respiratory system of organisms that directly intake oxygen from atmosphere and release carbon dioxide back into the atmosphere.

However, all amphibians and some other creatures like earthworms uses skin as respiratory organ on land. They intake air through their permeable moist skin.

Hence, option D is correct

i think that c)gold was found there

but i am not sure

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.