Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Question: The motion of stars in galaxies imply that there is about 10 times as much what as in the luminous objects we can see? Answer: mass
Figure 6.18 The diagram shows angular momentum for a circular motion.

Question: Cirrus, stratus, and cumulus are the main types of what? Answer: clouds
Clouds are classified on the basis of where and how they form. Three main types of clouds are cirrus, stratus, and cumulus. Figure below shows these and other types of clouds.

Question: What is the name of the group that rats are apart of called? Answer: rodents
Rats are mammals, but this class can be divided into more specific groups. Rats are in a group known as rodents. Rodents are gnawing animals that include beavers, mice, and squirrels.