Today's atmosphere is full of nitrogen and oxygen. these are
a. trace gases
b. variable gases
c. primary gases
d. secondary gases

Which of the following is not an effect of land substance

The african continent is home of the worlds largest desert and longest river . t or f

Ron is moving to oceania because his mining company recently opened a new operation there. to which of the following islands is ron most likely going? a. papua new guinea b. bikini atoll c. tahiti d. palmyra atoll