Stephen Hawking is one of the famous scientists in this century. He。 is now wh。eelchair bound and unable to f。eed himself or get in and out of b。ed alone. But he has refused t。o give in to the condit。ion. Now he is re。garded as one of the world's leading authorities on cosmology. Last year he was invited to China. He impressed us with his self-confident, humorous and witty conversations.