题目

Fifteen years spent in the field of education has provided me with many treasured moments. One of the most unforgettable   36   when I was teaching second   37   10 years ago. In May I decided to plan something special for the children; a Mother’s Day tea. We had put our heads together to   38   ideas of how to   39   our mothers. We practiced singing songs, memorized poems and wrote cards. We decided to hold our tea the Friday before Mother’s Day. I was surprised and   40   to learn that every mother was planning to attend. I   41   invited my own mother. F21、2008年北京奥运会的举办理念是“绿色奥运、科技奥运、人文奥运”．（1）火炬“祥云”使用的燃料是丙烷（C3H8），它的燃烧产物只有二氧化碳和水，符合绿色环保的要求．丙烷的摩尔质量是44g/mol，1 mol丙烷中约含有1.806×1024个碳原子．（2）为确保“水立方”的水质达到国际泳联最新卫生标准，泳池的水将采用“砂滤-臭氧-活性炭”净水工艺，其中活性炭净水是利用它的吸附性．（3）“反对运动员使用违禁药品”是北京2008“人文奥运”的重要体现．“乙基雌烯醇”（C20H32O）是一种违禁药品，它是由3种元素组成，该分子中碳、氢、氧原子的个数比为20：32：1．