PLEASE HELP! HURRY!

When we say that an experiment is controlled, we mean that __.

A.) the outcome is certain
B.) the theory has already been supported
C.) there is only one theory being tested by the experiment
D.) there is only one difference between experimental groups

How is the national wildlife refuge system similar to the pacific region coastal program? a. both programs are concerned with providing habitats for wildlife b. both programs are primarily concerned with preserving fish species c. both programs have set aside 150 million acres of land d. both programs are under the u. s. fish and wildlife service

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

When a gasoline engine burns gasoline, what type of chemical reaction is occurring?