题目

Once a rich boy bought a magic mirror（镜子）. When he a【1】home, he looked in the mirror. His face looked sad. He tried to smile and make f【2】faces, his face looked still sad. Then he did many happy things, but his face always looked sad.“Oh, what a terrible mirror! It doesn’t work!”he said a【3】.The next day on his way to buy some chocolate, he saw a little girl c【4】sadly. The rich boy went up to her and asked what had h【5】. The little girl said she couldn’t find her parents. “Don’t worry. I’ll help you,”the rich boy said. So they went to look for them t(   )25. The Great Wall is a long wall___________ runs more than 6,000 kilometres across northern China.A. what   B. where  C. how  D. which