Keystone predators can maintain species diversity in a community if they a) competitively exclude other predators. b) prey on the community's dominant species. c) allow immigration of other predators.
d) reduce the number of disruptions in the community. e) prey only on the least abundant species in the community.

yes it is   dangerous

explanation:

because that foot is discusting and could get you sick

oxygen is the first element in group 16 (via) of the periodic table. the periodic table is a chart that shows how chemical elements are related to each other. the elements in group 16 are said to belong to the chalcogen family. other elements in this group include  sulfur, selenium, tellurium,  and  polonium.  the name chalcogen comes from the greek word  chalkos,  meaning "ore." the first two members of the family, oxygen and sulfur, are found in most ores.

oxygen is by far the most abundant element in the earth's crust. nearly half of all the atoms in the earth are oxygen atoms. oxygen also makes up about one-fifth of the earth's atmosphere. nearly 90 percent of the weight of the oceans is due to oxygen. in addition, oxygen is thought to be the third most abundant element in the universe and in the solar system.