Where does the bulk of atmosphere oxygen come from

In science and physics what is the standard unit of measure for speed?

If the new moon happens on january 15th, what shape will it be on february 6th?

6–48 bananas are to be cooled from 24 to 138c at a rate of 215 kg/h by a refrigeration system. the power input to the refrigerator is 1.4 kw. determine the rate of cooling, in kj/ min, and the cop of the refrigerator. the specific heat of banana above freezing is 3.35 kj/kg·8c.