If a control group is not included in an experiment, it would be difficult to

Find the base of the experiment

Explanation:

If i tested how high my new jumping boots could go, then i would first have the person jump without them and then jump with them. I would use the control (without the shoes) and compare it to how high the person went WITH them on.

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.