dull joke的用法和樣例：
例句
- His joke provided some comic relief in what was really a dull speech.
他說的笑話給極沉悶的講話增加幾分輕鬆氣氛。 - Many people are shy to tell a joke, because they have once told dreary jokes, or they are afraid of showing their stupidness ,or hurting others.
很多人羞於講笑話，因為他們曾經講過一個讓人感覺沉悶的笑話，或者是他們害怕表現出自己的愚蠢，或是怕講笑話傷害到別人。
