World oil reserves amount to about 10,000 ej, and humankind uses energy at the rate of roughly 18 tw. if all our energy came from oil, and assuming there was no growth in energy consumption, estimate the time left until we would exhaust that 10,000-ej reserve.

Why does physical weathering speed up the processes of chemical weathering? a) physical weathering requires abundant water, as does chemical weathering. b) physical weathering produces fresh surfaces for chemical weathering to attack. c) chemical weathering can occur only on small surfaces, not large ones. d) chemical weathering requires salt, which is provided by salt wedging.

Compounds which are found naturally in the earth are called: a. ores b. composites c. rocks d.minerals

Which anatomical feature would you expect to find in the fossil remains of a nocturnal species?