通常我们认为main idea作为lecture和conversation的题，应该是肯定要对的。但是事实上我们往往容易错的是题。为什么？有什么理由整篇文章都感觉听懂了，居然做错了题？我们来看看做题的几个误区：
通常我们认为main idea作为lecture和conversation的题，应该是肯定要对的。但是事实上我们往往容易错的是题。为什么？有什么理由整篇文章都感觉听懂了，居然做错了题？我们来看看做题的几个误区：
误区一
从OG的题型分类上大家可以看到main idea属于basic comprehension的，包括两种：gist content & gist purpose。我们要先弄清楚这两个之间有什么区别？看看OG的解说：
内容主旨题：内容主旨题要求考生理解讲座或对话的主旨大意。材料有时会明确地提出主旨，有时则会很含蓄。内容主旨题会要求考生对所听到的信息进行归纳总结。
n典型问法：
? What problem does the man have?
? What are the speakers mainly discussing?
? What is the main topic of the lecture?
? What is the lecture mainly about?
? What aspect of X does the professor mainly discuss?
目的主旨题：目的主旨题主要考查的是对话的目的而非内容。此类问题较有可能出现在对话中，但偶尔也会出现在讲座中。
n典型问法：
? Why does the student visit the professor?
? Why does the student visit the registrar’s office?
? Why did the professor ask to see the student?
? Why does the professor explain X?
OG典型的提问法里我们会看到，不管是conversation还是lecture都有可能考查content，提问法里以what开头；反过来，purpose都是以why来提问的且以conversation为主的，所以同学在做题的时候要记得看清楚题到底是问what还是why，what则通常选内容，答案可能是在开头也可能自己归纳，why则选目的通常在开头。
同学们可能会觉得都是main idea都是主旨，应该没什么区别？举个例子来看看，假如我和A同学start a conversation说，A能不能借100块给我？然后开始七聊八聊恒大踢球赢了，各种兴奋……问目的我们要答的是借钱，问内容我们要答的是恒大。That’s the difference. 所以我们在做题的时候要区分清楚what和why。
误区二
不是所有的lecture都要问content，TPO经常是换着来问的What is the main purpose of the lecture?
比如：
12. What is the main purpose of the lecture? (TPO10 L2)
ATo describe the trade in food crops between Europe and Americas
BTo describe the introduction of American food crops to Europeans
CTo describe the influence of American food crops on traditional Europeans
DTo describe the difficulties of growing American food crops in European climates
解析：这是一道同学们很容易做错的题目，大部分都爱选C，选完还特别肯定自己没错，题目要求是purpose，而C项表达的是文章的后半部分的内容，food对欧洲历史的影响，而非题干所要的purpose。整个lecture讲述的是美国食物被引入欧洲的情况，正解就只有B。
误区三
总选择清晰的detail，失分！用排除法。
从上述的OG给出的说法，我们知道main idea有时候会明确给出，有时候比较含蓄，要自己总结归纳。大家心里犯愁了以为听得清楚的，或者反复听到过的内容就一定对了。其实不然。
例1 why does the man go to see his professor? (OG第二版 P157 track1)
ATo borrow some charts and graphs from her
BTo ask her to explain some statistical procedures
CTo talk about a report he is writing
DTo discuss a grade he got on a paper
正解是C，有些同学总是选B，他们分得清楚文章开头没有出现过A/D两项，觉得C概括得太厉害，感觉听到了statistical procedures，其实听到的是：
S: Uh, excuse me, Professor Thompson. I know your office hours are tomorrow, but was wondering if you had a few minutes free now to discuss something.
P: Sure, John. What did you want to talk?
S: Well, I have some quick questions about how to write up the research project I did this semester about climate variations.
把research project听成procedure了。听错了是硬伤，继续精听！巧的同学是听how to write来判断的，而且没有ask to explain的迹象。
例2 What is the purpose of the lecture? (TPO1 L1)
ATo explain the difference between two artistic styles
BTo describe a new art gallery to the class
CTo introduce an artist’s work to the class
DTo show how artists’ styles can evolve over time
正解C。A是大家*容易选的，套回笔记看看全文有没有对比过异同点，没有，只介绍了两幅画，同样的，B、D都没有。
例3 What is the main purpose of the lecture? (TPO18 L3)
ATo explore the use of spices in cooking in the Middle Ages
BTo explain the significance of spices for medieval society
CTo describe how the spice trade evolved in medieval Europe
DTo examine changes in the role that spices played in the Middle Age
正解B。A讲cooking是细节点，C讲trade是细节点，D更可以排除spices的role没有change，spices change了欧洲人的生活。
以上总结的是做主旨题的三大误区。我们有时候很难自己归纳出主旨，大家可以使用排除法，明确三项是错误的，选那个我们不太确定的。
排除以后还可以检验我们不确定的那一项是否一定是正确答案。1 该选项是否带有概括性，是否存在带有summary性质的词，这个词能不能概括整篇文章，还是只能概括其中一个清晰的detail；2 选项有summary是不是有具体的限定成分，限定成分表述往往是有误的。
例 What is the professor mainly discussing? (OG第二版 P166 track5)
AThe development of motor skills in children
BHow psychologists measure muscle activity in the throat
CA theory about the relationship between muscle activity and thinking
DA study on deaf people’s problem-solving techniques
正解C。A、D没有提过，B项限定成分in the throat，C项有概括性质。
