如图是实验室常用的一个装置，相关说法正确的是（　　）

根据短文内容和所给汉语提示，写出短文空白处各单词的正确形式。每空限填一词。
   At school many things happen to us. We may feel ____ （激动的）when we succeed in a school play. We may feel sorry if we lose an important ____ （比赛）. We want to keep the memory in our lives. How to keep memories? Our teacher, Mr. Smith, has taught us how to ____ （记住）things to make our own yearbook. A yearbook is a____ （种） of book which is used to memory wonderful moments. It’s usually made at the end of year. Last ____ （十二月）, we began to make our yearbook.____(首先) we chose the persons that had done something ____ （特殊的）, then some ____ （学生） interviewed them, some ____ （写）down their stories, others took photos of them. Finally our teacher helped us to put the things____ （一起）. Then we had our first yearbook.

“开元初，四方丰稔，城镇商铺林立，客商如云。丁壮之夫，不识兵器。”这段史料可以用于研究下列哪一位皇帝在位时期的社会经济状况（     ）

我国农业机械化程度最高、提供商品粮最多的粮食生产基地是（  ）