posted by Anonymous .
12. Justin usually blows his nose using Kleenex tissues. His snot keeps leaking through the tissue. He decided he's going to create and experiment to find out if there is something better.
a. type of tissue
c. amount of tissue
d. mess of the snots the tissue can hold
23. Harvester ants often strip a bush of all of its leave. Some people believe this helps the plant grow thicker, healthier stems. In an experiment, a student stripped off all the leaves from a set of plants. In a second set of identical plants, the student allowed ants to strip off the plants' leaves. In order to improve this experimental design, it is most important to add a set of plants that ___________