描述一次志愿经历 — 英语填空题
题目
汤姆在写一段自己做志愿者的短文，请根据句意和首字母提示补全短文（每空一词）。Last Saturday, I worked as a v______ (志愿者) at the school library. I helped to p____ (摆放) the books on the shelves. Some students came and I helped them f____ (找到) their books. I was busy but very h____ (开心的).