Which of these is an element?
a. carbon dioxide
b. air
c. water
d. carbon
(i wanna be sure i am right on this questions so)

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

Building glycogen from glucose molecules is an example of