failure at a certain period of time is acceptable.
有时失败是可以接受的（直译就是 某个时候的失败是可以接受的）
many jazz clubs during this period had balck perfomers ,but few allowed them to watch the show by part of the audience.
这个时期许多爵士俱乐部都有黑人表演者 但是观众很少能看到他们的表演
mean dogs are used to guard this property厉害凶猛的狗都是用来看管物品财产的