I NEED HELP
PLEASE READ THE QUEUSTION AND AWNSER IT'S A MULTI ANSWER.

All living organisms are composed of a. only one cell. b. at least 100 cells. c. at least three cells. d. one or more cells.

Ascientist is conducting an investigation that involves water, silver, carbon dioxide, and oxygen gas which group of statements best describes all of the materials he is using in the investigation?

When an object is moving away from you while still making a sound, the pitch of the sound is perceived to a. lower b. unchanged c. fluctuating d.higher