In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

Which supports the idea that birds and butterflies both have wings but they do not have a common ancestor with wings? a. the wings are analogous structures that evolved differently and do not have a similar internal structure. b. the wings are homologous structures that evolved differently and do not have a similar internal structure. c. wings of birds are vestigial structures, but the wing structures of bats are not vestigial. d. wings of bats are vestigial structures, but the wing structures of birds are not vestigial

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

When a septic tank backs up a goes in to clean it out