to come across後面多半指人或事物，是意外遇到(to meet someone or something by chance)
例如﹕
I came across Mr. A, my former colleague, at the store yesterday.
昨天我在商店偶遇老同事A先生。
He felt a little fit awkward when he came across his ex during a social function.
他在一次社交中意外碰到前妻，感到有些尷尬。
How did you come across such a valuable photo of your family?
你怎麼找到府上這麼寶貴的相片?
Mr. B has recently come across some rare books at a flea market.
B先生最近在跳蚤市場偶而找到幾本罕見的書。
但to come by又是指獲得或取得(to get or to obtain)(後面多半跟事物)
例如﹕
How did you come by such a good-paying job ?
你怎麼取得這份高薪工作？
Mr. A has come by a beautiful painting at an auction.
A先生在拍賣場獲得一幅漂亮的畫。
Be patient; you will soon come by an opportunity to publish your articles.
耐心些！你很快有機會發表你的大作。
(7)to cut back與to cut in:
to cut back指減少，多半指生產方面(to reduce, generally refer to production)
例如﹕
Due to a trade downturn, the factory has to cut back(on) production.
由於經貿欠佳，工廠必須減少生產。(on可省去)
If he doesn't cut back his expenses, he may face financial difficulty.
例如他不減少開支，就會面臨財政困難。
而to cut down是指消費(consumption)方面的減少﹕
In order to keep herself slender, she always cuts down her meat intake.
為了保持身材苗條，她常常減少肉食。
By cutting down on luxuries, you may save more money for a rainy day.
減少購買奢侈品，你能省更多錢，以備不時之需。
(有時在cut down後加介詞on)
但to cut in是指打斷或開車時突然超前(to interrupt or sharply turn the car in front of other's)
例如﹕
It is rude to cut in on other people's conversation without permission.
未經許可而打斷別人說話是不禮貌的。
(也可用to cut into)
Don't keep cutting in while driving on the highway.
在高速公路上開車，不可突然急轉超前。
American children are always taught not to cut in(或into) line under no circumstance.
美國孩子常被教導絕對不可插隊。
(8)to die down與to die for:
to die down是指降低(to decrease)
例如﹕
The jobless protest may die down if the company president will talk to them.
假如公司總裁與他們對話 ，失業者的示威也許會降溫。
His anger is dying down after his wife's explaining the true situation.
經太座解釋實際情況後，他的怒氣逐漸消失。
The tension between Taiwan and China has died down under Mr. Ma's leadership.
在馬先生領導下，台灣與中國間的緊張局勢已經降溫。
但to die for 是指盼望或渴求某事 (to long for; strong desire for something)
例如﹕
Many people are dying for fame and money.
許多人渴求名利。
To publish a book is what Bob has been dying for.
出一本書是Bob一直所渴望的。
Dying for a beautiful house and an expensive car makes Mr. A work harder.
為了渴求有美麗房子和昂貴汽車，A 先生工作更賣力。
(9) to drink in與 to drink up:
to drink in 是注意或熱心地細聽 (to listen carefully or enthusiastically)
(後面多半跟某一事物)
例如﹕
If there is any gossip, his wife will drink it in and spread it fast.
如有流言蜚語，他太太就會傾聽，同時很快傳播。
( 兩個it 都是指gossip)
Sitting on the couch, I drank in the beautiful music.
我坐在沙發上，陶醉於美妙的音樂。
I have drunk in all your lecture and really enjoyed it.
我全神貫注傾聽你的演講，十分喜歡。
Drinking in what Ed has told me, I start to question his honesty.
細聽Ed 所說的一切，我開始懷疑他的誠信。
但 to drink up是指喝完( to finish drinking)
(後面多跟飲料)
例如﹕
When a Chinese host proposes a toast to you, he usually drinks up the entire glass.
當中國主人向你敬酒時，他通常都喝完全杯。
