There are two, two-sided dishes in the pillbug experiment. In one dish, you should have placed sand in both sides. In the other dish, you should have placed in one side and in the other.

The correct answer is "sand, cornstarch".

Explanation:

Two basic criteria that must be included in any experiment is using a control and test one variable at a time. In this case, the behavior of pill bugs in cornstarch is going to be studied. The dish serving as control will have sand in both sides. And the dish serving as the experimental approach must have sand in one side and cornstarch in the other. By having this configuration this dish serves as the focus of the study, including the variable (cornstarch) and the control (sand).

kelp are large brown algae that live in cool, relatively shallow waters close to the shore. they grow in dense groupings much like a forest on land. these underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.

e) all of the above