1、ultimate

最后的；最終的

He said it is still not possible to predict the ultimate outcome.

他說現在還無法預料最終的結局。

The ultimate aim is to expand the network further.

最終目的是為了進一步拓展該網絡。

最根本的；最基礎的；最原始的

Plants are the ultimate source of all foodstuffs.

植物是所有食物的最根本來源。

The ultimate cause of what's happened seems to have been the advertising campaign.

出事的最根本原因似乎在于那場廣告宣傳活動。

最重要的；最強大的；至高的

the ultimate power of the central government.

中央政府的至高權力

Of course, the ultimate authority remained the presidency.

當然，擁有最高權力者依然是總統。

2、challenge

挑戰;難題

I like a big challenge and they don't come much bigger than this.

我喜歡大的挑戰，而所有挑戰中再沒有比這更大的了。

The new government's first challenge is the economy.

新政府面臨的第一個難題是經濟問題。

(成功地)應對挑戰，迎接挑戰

The new Germany must rise to the challenge of its enhanced responsibilities.

一個嶄新的德國必須迎接挑戰，承擔更多的責任。

They rose to the challenge of entertaining 80 schoolchildren for an afternoon.

他們一個下午成功接待了80名學童。

懷疑，質疑(真實性、價值、權威等)

Democratic leaders have challenged the president to sign the bill.

民主黨領袖對總統簽署這項法案提出了質疑。

The move was immediately challenged by two of the republics.

此項動議立即遭到其中兩個共和國的反對。