If I wanted to show you a picture of all the dog breeds in the world, and I put 30 or 40 of them on a slide, it would take about 10 slides because there about 400 breeds of dogs in the world.
如果我想给你们看看世界上狗的所有品种。 每一个照片上放上30-40个，会用去10个照片。 因为世界上有大概400种狗。