Which gas in Earth's atmosphere has increased over time due to burning fossil fuels?
oxygen
nitrogen
water vapor
carbon dioxide

Atsunami usually is the result of a. a nearby underwater earthquake. b. the winter monsoons. c. seismic activity in the eastern pacific ocean. d. hurricane-force winds.

According to the earth science reference tables, during which geologic time period were the continents of north america, south america, and africa closest together?

The ozone hole is at its biggest each year in the ? hemisphere in the ? season.