1、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。

2、reaction

反應；回應；反響

Reaction to the visit is mixed.

對這次訪問的反應不一。

The initial reaction of most participants is fear.

多數參與者的最初反應是恐懼。

反對;反抗;抵制

All new fashion starts out as a reaction against existing convention.

所有新時尚都是從打破現有常規開始的。

Her three years of freedom seemed like a reaction against that childhood.

她那3年的自由仿佛是對孩童時代的反叛。

抵制；抵觸

Premature moves in this respect might well provoke a reaction against the reform..

在這方面不成熟的舉動很可能引發對改革的抵觸情緒。

The government response seems to be the result of strong public reaction against the police apathy.

政府的回應似乎是公眾強烈抵制警察冷漠執法的結果。