题目

听下面一段独白，回答问题。 （1） What is the speaker? A . A teacher. B . An editor. C . A student. （2） What is necessary for a volunteer? A . Communication skills. B . High scores. C . Experience. （3） What's the best reason for taking the job? A . To learn to write. B . To make money. C . To have fun. （4） When are volunteers expected to start working? A . Right after the meeting. B . Tomorrow. C . Next week.在透明塑料片上滴一滴水，放在报纸上就能把字放大，原因是什么呢？答：塑料片上的水滴形状是中间厚，边缘薄，相当于一个______，纸上的字放在离它______的位置上，就能成一个正立、放大的______像．