题目

One of my wonderful memories is about a Christmas gift. Unlike other gifts, it came without wrap(包装) On September 11th, 1958, Mum gave birth to Richard. After she brought him home from hospital, she put him in my lap, saying,“ I promised you a gift, and here it is.” what an honor! I turned four a month earlier and none of my friends had such a baby doll of their own. I played with it day and night. I sang to it. I sang to it. I told it stories. I told it over and over how much I loved it! One morning, however, I found its bed empty. My doll was gone! I cried for it . Mum wept an制备粗硅的反应为：SiO2+2C Si+2CO↑，其中氧化剂与还原剂的物质的量之比为 A．1 : 3       B．1 : 2      C． 3 : 1           D．2 : 1