PLEASE HELP! The purpose of the serous fluid in the pericardial cavity is

A) to carry critical nutrients like oxygen to the heart

B) do you provide CA2= to ions needed for muscle contractions

C) decrease friction between the layers of the heart as contractions

D) to lubricate the walls of the blood vessels to decrease resistance to blood flow

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).

the "power" of a lens is its resolution power, or its ability to distinguish between to closely located points. with the low power lens, it is likely you will see the rough form of the hay and maybe some movement of dots around the hay. however, when observed with the high power lens, the detailed features of the hay become visible and the microbes being grown are more clearly visible.

i hope this you

the endomembrane system i think