Describe how water quality changes from the source of a river to the mouth.

Explain why ecosystem diversity results in species diversity in a healthy biosphere

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?

Which of these parts of the membrane large moecules pass through it ?