it is fair 这个句型一般什么情况下用?

意即：‘。是公平的”句首It 是形式主语,后面的that 用以引导主语从句,做真正主语It is fair that those who do the damage should make restitution 损害者应给予赔偿是公正的。It is not fair that I always have to do all the cleaning。总是我来打扫卫生真是太不公平了。