A Friend
When you read an English book, you often come across new words. You might try to guess what the words mean from the words you know, but when you cannot guess the meanings of new words at all, what should you do?
You have a good friend then. From him you can learn what a word means, how to pronounce a word, how to use a word, and so on. This friend can always be with you, and you can always ask him to help you. Do you know who this friend is?
It is a dictionary. You can learn some important things about words from it, so you must know how to use it.
中文译文
朋友
当你读英语书时，你经常会碰到新单词。你可能试着从你知道的词中猜这些词的意思，但是当你无法猜出这些词的意思时，你该怎么办呢？
这时你有一个好朋友。从他那里你可以学到单词的意思、发音及用法等。这个朋友可以经常伴你左右，你可以经常请他帮忙。你知道这个朋友是谁吗？
他就是字典。你可以从他那里学习有关词汇的众多重要知识，所以你必须学会如何使用字典。
Vocabulary
come across 碰到 guess 猜测
