main idea 和 topic 还有 key word 的区别

请记住最基本的定义,就不会如此犹豫不定了：
Topic ==> 题目/主题 （一篇文章的题目）
Main idea ==> 主要思想 （一片文章想要表达的主要意思）
Topic 相当于金字塔的塔尖,是文章的最高点（即主题思想）
Main idea 相当于金字塔的塔身,是文章的主要脉络.

Is Failure a Bad thing?
Failure is a common occurrence in our daily life.Whatever we do,there are always two possible result：success or failure.Although everyone wants to succeed in what he tries,sometimes failure can‘t be avoided.Different people hold different attitudes toward failure.When faced with it,some can stand up to it,draw a useful lesson from it and try their best to fulfill what they are determined to do.Others,however,lose heart and give in.They do nothing but complain about themselves and objective conditions.