对话文本
Susan: what's up, Nicole?
Nicole: I pulled an all-nighter working on my election speech.
Susan: no wonder you look like a basket case! Did you finish your speech?
Nicole: yes, at 6 a.m.
Susan: that must be a load off your mind!
Nicole: it's not. I've got to give the speech tomorrow in front of 1,500 people. I'm a nervous wreck!
Susan: just remember the old rule of thumb: imagine your audience naked.
Nicole: that's gross. Why would I want to do that?
Susan: according to conventional wisdom, it'll make you less nervous.
Nicole: only practice will do the trick.
Susan: okay, let's hear the speech.
Nicole: good afternoon, everyone. There are four candidates running for president. You think you have several choices. In reality, you have just one choice: me!
Susan: you can't say that. You'll turn off your audience immediately.
Nicole: it sounds like I have a big head?
Susan: I'll say!
实战美国口语
Basket case: someone or something in a useless or hopeless condition处于无助境况的人(或事)
That manager has been a basket case here since his wife left him.
自从太太离开他后,那位经理就变得意志消沉。

To have a big head: arrogant; too proud of oneself 自负，骄傲自大

Conventional wisdom: a widely held belief普遍的看法，一般人的意见，公众态度，大众意见，(社会上的)传统观念

to do the trick: to achieve the desired results达到目的；达到(预期的)效果；完成某项任务；发生效力

I'll say: yes, definitely 当然

Load off one's mind: a relief 松了一口气

nervous wreck: a person feeling very worried 极度紧张的人，精神高度紧张的人

No wonder: it's not surprising 难怪

To pull an all-nighter: to stay up all night to do work 通宵工作

Rule of thumb: a useful principle 经验法则

To turn off: to cause to feel dislike or revulsion使(某人)厌烦(或沮丧)，使失去兴趣(或热情)，使不喜爱
The film really turned us off.
这部影片真让我们烦透了。
She turned right off mathematics when they got the new teacher.
来了新老师后，她就对数学不再感兴趣了。