“There is considerable disagreement among scientists over how likely such a catastrophe is to occur.”
You're watching the news. Recently a scientist has warned that a nuclear power plant in your area is unsafe. The company that runs the plant says it's safe. The news reporter tells what other scientists think.
You're chatting with someone at a party who you haven't spoken with very much. He just told you about his job. You ask for more information about it.
You're leading a meeting to discuss a change in your division at work. One of the managers is complaining because his group doesn't have enough people, and the company won't let him hire more. His complaints aren't helpful, so you switch the topic...
You're having a meeting at work to discuss way to solve a problem. A coworker suggests one solution, but it would be too expensive. You reject his idea.
You're talking with a friend about a band that he really likes. You tell him that you don't like them as much. He can't believe it and tries to convince you that they are great musicians. You explain why you don't like their music.