What is the difference between a debit card and a smart card?

Why are radio observatories located in valleys far away from urban centers? a. to shield them from electromagnetic interference b. to avoid sound pollution c. to avoid disturbing people living in the city d. to shield them from water vapor

In a person dependent on a drug, occurs when the drug leaves his or her system quickly or for a prolonged period of time. a. addiction b. withdrawal c. independence d. relapse

Based on the graph, how is coal consumption likely to affect future generations? a. the higher our current rate of consumption, the less coal will be available in the future. b. current rates of consumption are irrelevant because new coal will form in the future. c. the lower our current rate of consumption, the more slowly coal will be replenished for the future. d. regardless of current rates of consumption, coal will always be available.