I believe its C. Atomic numbers represent the number of protons, thus, it can be concluded that an oxygen atom does indeed have more protons than a hydrogen atom :)
B. drinking can lead to health problems
D. 30 to 60 is the answer i think... I read about it on a dental health website.
According to the health monitoring device manufacturer Microlife, bones account for about 15 percent of total body mass in men. In women, bones account for roughly 12 percent of total body mass
