If it's zero degrees outside today and it's supposed to be twice as cold tomorrow, how cold is it going to be?

If it's zero degrees outside today and it's supposed to be twice as cold tomorrow, how cold is it going to be?

如果今天外面是零度，明天应该是现在的两倍冷，那么明天会有多冷呢?

-- Steven Wright 史蒂文赖特