描述查词经历的表达 — 英语填空题
题目
Tom 遇到一个生词 dictionary，他去图书馆请老师帮忙。请根据对话和首字母提示补全句子，每空一词：
1. Tom didn't know the meaning of the word, so he a________ the teacher for help.
2. The teacher told him to look the word u________ in a dictionary.
3. Tom thinks looking up new words in a dictionary is a good w________ to learn English.