While being skeptical can be a healthy way to avoid getting taken advantage of, being pessimistic - that is, always assuming the worst - can have major negative consequences on your life.

虽然质疑是一种回避被利用的健康方法，悲观，总假设最糟糕情况对你的生活可能带来很大得消极影响。

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This year,when you have two-thirds being pessimistic about American foreign policy, you have a larger percentage saying maybe it will be better if Iran has nuclear weapons."

VOA: standard.2010.08.06

We all know that there are many reasons to be pessimistic about the direction of housing prices, the number 1 reason being the lack of credit.

FORBES: Top Ten Reasons to Be Optimistic About Homebuilders

Dr Goldman said he could see "no reason to be pessimistic" although further safety tests would be needed and the technique still needed to be refined before being used in people.

BBC: Skin 'may restore' diseased MS brain