题目

阅读理解 We went on a school trip to New York. We had a good time. There were twenty-four students and three teachers. It was a five-day trip, and we visited some attractions (景点). We stayed at a hotel and six people had one room. We often had our meals out of the hotel—there were a number of restaurants nearby. We went around the city, and we were really given quite a lot of freedom(自由). So long as (只要) we were back to our rooms by 10 p.m., we could go where we wanted to. I was surprised at how safe I felt walking around New York in small groups. My friends and I enjoyed our 从安全、环保、节能、简便等方面考虑，实验室制取氧气的最佳方法是（      ） A.通电使水分解                  B. 氯酸钾加热分解 C.高锰酸钾加热分解              D.过氧化氢催化分解