4. 有些选项构成明显的对比，往往可以通过它们之间的差异，缩小听音范围。
例题解析3： (Cambridge 5Test 3 Section 2 Question 20)
With regard to their English， the speaker advises that students to
A. tell their lecturers if they have problems understanding.
B. have private English lessons when they arrive.
C. practice their spoken English before they arrive.
解析：B、C选项存在明显对比，一个是到英国后加强英语，一个是来英国前加强英语;关键词分别划在when和before， 来进行区分，同时可以先排除A。
(录音：Having said that though， I’m afraid the lecturers will make little or no allowance for the presence of non-native speakers in the audience， so anything you can do to improve your spoken English， even beyond the pretty high level most of you have already reached will make your stay with us that bit more fun for you. Some extra practice before you arrive is worth more than， for example， private lessons afterwards when you won’t really have time.)
