Earth was formed approximately 4.6 billion years ago. true false

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

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?

There are fewer than 100 naturally occurring elements in the universe, but there are millions of different unified substances. explain how this can be true.