drug|noun|anything used as a medicine or in making medicine; a chemical substance used to ease pain or to affect the mind
improve|verb|to make better; to become better
kind|adjective|gentle; caring; helpful
negative|adjective|not good; having an attitude against; (in science) of a number less than 0; opposite of positive
positive|adjective|good; very sure or certain that something is correct; full of hope that something will lead to good; opposite negative
study|verb|to make an effort to gain knowledge by using the mind; to examine carefully
