1、check out

結賬退房;結賬離開(診所);給…辦理結賬手續

They packed and checked out of the hotel.

他們收拾好東西，辦理了退房手續。

I was disappointed to miss Bryan, who had just checked out.

我非常失望沒有見著布賴恩，他剛退房走了。

了解清楚;核實;查實

Maybe we ought to go down to the library and check it out.

或許我們應該去趟圖書館，查個明白。

We ought to check him out on the computer.

我們理應在電腦上查清他的資料。

經證實是對的;符合要求

She was in San Diego the weekend Jensen got killed. It checked out.

詹森遇害的那個周末她在圣迭戈，后經查證情況屬實。

Everything checks out.

查過了，一切正常。

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。