All paragraphs should be based on the same topic but not necessarily the same idea. for example, in writing an essay about the effect of drugs, each of the paragraphs should tell of the effects of drugs but may be specific to one type of drug.
Topic: Effects of Drugs
paragraph 1: introductory paragraph
paragraph 2: effect of marijuana
paragraph 3: effect of cigarette
paragraph 4: effect of alcohol.
hope this helped :)
