Which nonmetal is used as a food?

O rock gypsum
O rock salt
O quartz
O talc

Which of the following will not cause mass extinction? a. drastic change is weather b. geological change c. both a and b d. none of the above

Where can dna be found in a prokaryotic cell

Which of the organisms listed below performs nitrogen fixation? a. legumes b. plants c. bacteria d. fungi