1、probably

大概；或許；可能

The White House probably won't make this plan public until July.

白宮可能要等到7月份才會公開這個計劃。

Van Gogh is probably the best-known painter in the world.

凡·高可能是世界上最知名的畫家。

（用于緩和語氣）大概，或許，可能

He probably thinks you're both crazy!

他可能認為你們兩個人都瘋了！

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。