根据短文内容和首字母提示，把所缺单词的正确形式完整地填写在短文下的横线上。

     At school many things happen to us. We may feel excited when we succeed in a school play. We may

feel sorry if we lose an important (1)g______. We want to keep the memory (记忆) in our lives. How to

keep memories? Our teacher, Mr. Smith, has taught us how to (2)r______ things to make our own yearbook.

A yearbook is a kind of book which is used to memory exciting moments. It's usually made at the end of

year.Last (3)D______, we began to make our yearbook. First we chose the persons that had done something

special, then some students interviewed them, some (4)w______ down their stories, others took photos of

them. Finally our teacher helped us to put the things (5)t______. Then we had our first yearbook.

1991年我国著名化学家张青莲教授，精确测定了铟（In）元素等相对原子质量新值．铟元素的核电荷数为49，相对原子质量为115．铟原子的核外电子数为（　　）

A．115

B．49

C．66

D．164