1、I'll go to the sea for a month's holiday. 这里为什么不能说 a holiday of a month?
同样的The weight of a bike is too much for a little boy.为什么就不能说A bike's weight is too much......?
Ten head of cattle are grazing in the fields.
3、One thousand pounds is a small sum to run a company.为什么pounds了后面要用is？