keep an eye

「keep an eye」是「keep an eye open」（要有一隻眼睛是睜開的）， 也就是「留心、注意」的意思， 例如：

We should keep an eye on the notice board for forthcoming events.（我們應密切注意布告欄，關注即將發生的事件。）

A neighbor volunteered to keep an eye on the kids.（有位鄰居自願照顧孩子們。）

I've lost my pen could you keep an eye out for it when you clean the classroom?（我的筆不見了，你打掃教室時可以幫我留意嗎？）

ferocious

「ferocious」是「激烈或凶猛的」，例如：

The storm grew more and more ferocious with each second.（暴風雨分分秒秒都變得愈加猛烈。）

Ferocious competition has pushed computer prices down.（電腦的激烈競爭使得售價下滑。）

The house is guarded by a ferocious dog.（這房子由一隻兇猛的狗看守。）

fetch

「fetch」是「去拿或去接……回來；恢復 」，例如：

Peter has fainted; this bucket of water should fetch him round.（彼得暈倒了，這桶水應該可以讓他恢復清醒。）

The painting would fetch millions of dollars if it was sold on the open market.（這幅畫如果公開出售，可以賺回數百萬美元。）

Why don't you fetch your new composition over this evening? We'd like to hear it.（你何不今晚拿新作品過來？ 我們想聽聽看。）