For this part, you are allowed 30 minutes to write an essay on the topic: What do you think will be the world's greatest problem in fifty years time. You should write at least 120 words following the outline given below in Chinese: 试分析五十年后世界上可能出现的重大问题,内容应包括: 1. 描述一下当前的隐患; 2. 未来问题的出现形式及其严重性; 3. 提供解决问题的可行性方案。