1、vulnerable

脆弱的;易受傷害的

Old people are particularly vulnerable members of our society.

老年人是社會中尤為明顯的弱勢群體。

易感染（某種疾病）的；易患病的

People with high blood pressure are especially vulnerable to diabetes.

有高血壓的人尤其易患糖尿病。

Plants that are growing vigorously are less likely to be vulnerable to disease.

生命力強的植物不容易得病。

易受傷害的;易受影響的

Their tanks would be vulnerable to attack from the air.

他們的坦克易受到空襲。

a table showing which cars are most vulnerable to theft.

易被盜車輛一覽表

2、challenge

挑戰(zhàn);難題

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

我喜歡大的挑戰(zhàn)，而所有挑戰(zhàn)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(jīng)濟問題。

(成功地)應對挑戰(zhàn)，迎接挑戰(zhàn)

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(zhàn)，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(zhì)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(tǒng)簽署這項法案提出了質(zhì)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。