阅读下面的材料,按要求作文。有位渔夫出海捕鱼,从海里捞到一颗大珍珠,这颗珍珠,晶莹圆润,渔夫爱不释手。美中不足的是,珍珠上有一小黑点。渔夫心想,如果将小黑点去掉,珍珠完美无瑕,就会成为无价之宝。于是,他就耐心地剥剔黑点。可是,去掉一层,黑点仍然存在;再去掉一层,黑点还 Read the material below and write the composition as required. A fisherman went out to fish and fished a large pearl from the sea. The pearl was crystal-clear and the fisherman put it down. The only drawback is that there is a small black spot on the pearl. The fisherman thought that if the black spots were removed and the pearls were perfect, they would be invaluable. So he patiently stripped black spots. However, after removing one layer, black spots still exist;