重點(diǎn)講解：
1. up and down
上上下下；來(lái)來(lái)回回；
eg. I strolled up and down thoughtfully before calling a taxi.
我踱來(lái)踱去仔細(xì)思量后叫了一輛出租車(chē)。
eg. He jigged up and down with excitement.
他激動(dòng)得又蹦又跳。
2. come upon
偶然碰到（或發(fā)現(xiàn)）；
eg. I came upon an irresistible item at a yard sale.
在一次庭院拍賣(mài)會(huì)上，我偶然發(fā)現(xiàn)了一個(gè)忍不住想買(mǎi)的東西。
eg. I may come upon something that'll throw some extra light on this.
說(shuō)不定我會(huì)發(fā)現(xiàn)什么新線(xiàn)索，把這件案子的眉目弄得更清楚些。
3. be finished with
完成；不再做（…）的；（同…）不再打交道的；（對(duì)…）不再感興趣的；
eg. One suspects he will be finished with boxing.
人們猜想他不會(huì)再打拳了。
eg. And now you are finished with the exciting and demanding years of college ready to start on a fine career.
但是現(xiàn)在，你已經(jīng)結(jié)束了令人激動(dòng)的和需要付出努力的大學(xué)歲月，準(zhǔn)備要開(kāi)始一個(gè)美好的生涯了。