If you had a bad day take these points

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

To earn college credit for ap courses that students take in high school they must

Which of these is a disadvantage of hydrogen fuel cells? a. engines that use hydrogen fuel are more efficient than gasoline-powered engines. b. the only emission produced by hydrogen fuel cells is water. c. hydrogen fuel is continually available and useful for heating. d. hydrogen fuel is often purified in a process that emits lots of greenhouse gases.