1. 认识这个词（基础篇）
词：slippery slope
英英释义：a bad situation or habit which, after it has started, is likely to get very much worse
例句：Once you start to lie, you are on a slippery slope.
2. 体会这个词 （进阶篇）
“slippery slope”是个习惯表达，它的字面意思是“光滑的斜坡”，常用来表示“滑向深渊的道路”，如果不及时采取措施这种状况就会变得更糟。它是个非常形象、适合用在口语和写作中的精彩表达，当我们想表达“something becomes worse”时就可以用 slippery slope 来替换。
比如我们常说，撒了一个谎，结果需要无数个谎言来弥补，结果就会一步错步步错，就可以用“slippery slope”说成：
Once you start to lie, you are on a slippery slope.
或者
The first fib can put you on a slippery slope to bigger lies.
我们还常说“拆东墙补西墙”，时间久了就会越来越糟糕，债台高筑。这时就可以说：
We've been on a slippery slope of borrowing more money to pay off the debts we already owe.
或者
Over-borrowing will inevitably lead the borrower down a slippery slope.
《经济学人》中也经常用到 slippery slope，比如在报道“协助死亡”（assisted dying）时说：
And evidence from places that have allowed assisted dying suggests that there is no slippery slope towards widespread euthanasia.（这句话是说允许协助死亡并不会导致越来越多的人选择安乐死）
slippery slope 和我们之前学过的 go downhill 差不过，可以借此复习一下 downhill（点击直接跳转）的用法。
3. 从认识到会用（作业）
1）翻译下面的句子：
他的傲慢与固执将注定他会走向失败。
His arrogance and obstinacy will lead him down a slippery slope to failure.
（参考翻译: His arrogance and obstinacy will lead him down a slippery slope to failure. ）
2）结合自己的生活、学习、工作、兴趣等，想象在什么语境下会用到这个表达。先简要描述这个场景，再造句。
场景： 商业
造句：Then comes geopolitics. With their hubs in Seattle and Toulouse,Boeing and Airbus are among the West’s largest exporters and a rare example of an industry in which China cannot compete. It would be depressing , but not impossible, if safety decisions were influenced by trade tensions. Over time, China and India may insist that the duopoly make more aircraft within their borders, to capture more jobs and intellectual property. That could require a restructuring of how both firms manufacture. Rows over aircraft emissions will further complicate the debate. There is no slippery slope towards the golden age for the world’s aircraft duopoly.
