The gummy bears not placed in water or salt water serves as a control for comparison.

True

Explanation:

The control is the variable or the group that you do not change. It will serve as a baseline for comparison or it can also be used to validate whether the independent variable caused the change.

The gummy bear that was not placed in water or salt water is the control because the independent variable was not applied or tested on it.

i'd say that the moon rock is about 2.2 billion years old.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: