From the primitive time, animals have played a significant role in people's life: their meats are supplies of food, and their fur and bones for blothing and medicines. However, with the dramatic development of technology, we are gradually independent of animals for life's activities. Some people belive that, in the future, it is no longer necessary to exploit animals for human's purpose. I totally agree with this viewpoint since we can eliminate our reliance by using alternative products, which are not animal - related.