Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes. b. it burns more cleanly than crude oil products. c. scientists have developed new ways of extracting it. d. during its extraction, groundwater can be contaminated.

Why do we always see the same side of the moon? 1. the moon rotates at the same speed as the earth rotates. 2. the moon revolves around the earth at the same rate the earth rotates on its axis. 3. the moon rotates on its axis at about the same speed as it revolves around the earth.