Part BDirections ：Read the text below. Write an essay in about 120 words, in which you should summarize the key points of the text and make comments on them. Try to use your own words. A millionaire in New York suffered from a severe eye disease. He got a famous doctor to treat his eye. The doctor performed a minor operation on the millionaire, gave him some medicine and advised him to avoid bright light for one month so as to add to the treatment and ensure speedy re­covery. On arriving home, the millionaire immediately acted on the doctor's advice. He closed all his windows，replaced the colorful curtains with dark heavy ones，removed his bright ceiling lights and used dim bulbs. In a word，he went to great lengths to make his house completely dark. Two weeks later, the doctor paid a visit to the millionaire to enquire about his recovery. To the doctor' s astonishment, everything in the house was made dark and dull. "Just look at ail this," said the millionaire proudly. Not the lowest beam of light inside. I spent $5,000 on the changes to the house. I followed your advice faithfully." "You sure did," replied the doctor, but he found it hard to say that it was a matter of plain common sense that the millionaire could have bought a pair of sunglasses，which would cost much less, rather than spending so much money making the house darker, in order to avoid bright light.