Describe why this is a controlled experiment. A. Only one variable is changed
B. two variables are changed
C. the plants grew tall in the control group
D. the plants grew tall in the experiment

What are four key elements of the study of economics?

Aperson with age is more likely to catch diseases that healthy people usually don’t catch.what are these infections called?

Choose one animal (cheetas) and research on the internet what has contributed to this animal becoming "endangered" or "threatened." what animal you have chosen? how long has the animal been endangered or threatened? what has contributed to this animal’s endangered or threatened status? why is it important to save this animal from extinction? after researching and gathering facts, write a 350-word letter from the point of view of an animal rights' activist. be sure to include at least five facts that you learned from your research.