Why are fuel cells considered a "clean" energy source?

Complete the statement about memory improvement. ( )involves organizing and breaking down information into easier groups to expand capacity. rehearsal is the verbal repetition of information. these techniques are especially important for the improvement of ( ) memory.

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon