Forests are useful in fighting the effects of air pollution because they produce
A. Carbon B. Oxygen C. Hydrogen D. Carbon dioxide

Describe how gravity and convection work together to move the plates in the plate tectonics theory

The areas with the highest population density in europe are most likely to be

Plz 20 ! in a citizens elect the president as head of government separately from the legislature? a: parliamentary democracy b: communist state c: presidential democracy d: autocratic state