After a rain, a puddle of water remains on a sidewalk. after a day of sunshine, the puddle is gone. what caused the water to disappear?

In what for do plants utilize nitrogen? why do they need nitrogen?

According the inverse square law, doubling the distance from the source of the sound, a speaker, for example, will drop the sound 6 db each time. if you were standing in the back of an auditorium, 32 feet away from a speaker not using any amplification, would you be able to hear a speaker clearly? why or why not?

Organize the word parts according to where they appear in a medical term.