STH DIFFICULT 困难的事, [C,U] something that tests strength, skill, or ability, especially in a way that is interesting

挑战，具有挑战性的事物:

The company is ready to meet the challenges of the next few years.

公司已准备好迎接今后几年的挑战。

I relish the challenge of rebuilding the club.

我喜欢重建俱乐部这个挑战。

Martins now faces the biggest challenge of his career.

马丁斯现在面临他事业上最大的挑战。

a new and vibrant initiative to meet the challenge of the 21st century

一项迎接 21 世纪挑战的充满生气的新举措

the intellectual challenge of postgraduate research

研究生研究的智力挑战

QUESTION STH 质疑某事, [C] when someone refuses to accept that someone or something is right and legal

〔对某事的正确性、合法性等的〕质疑:

a direct challenge to the Governor's authority

对总督的权威提出直接的质疑

The president faces a strong challenge from nationalists.

总统面临民族主义者的强烈质疑。

The strike represented a serious challenge to the government.

此次罢工对政府提出了严重的质疑。

They decided to mount a legal challenge to the decision.

他们决定对这项判决提出上诉。

COMPETITION 竞争, [C] when someone tries to win something or invites someone to try to beat them in a fight, competition etc

挑战，〔比赛等的〕提议:

They are ready to mount a challenge for the championship.

他们准备发出挑战争夺冠军。

They threw down the challenge that he couldn't wash 40 cars in one hour (=invited him to try to do it) .

他们激他，说他不可能在一小时内洗 40 辆汽车。

The Prime Minister narrowly avoided a leadership challenge last year.

去年首相侥幸避过了一次对其领导地位的挑战。

STOP 停止, [C] a demand from someone such as a guard to stop and give proof of who you are, and an explanation of what you are doing

喝停盘问

IN LAW 法律方面, [C] [law] a statement made before the start of a court case that a JUROR is not acceptable

〔开庭前律师〕反对某人任陪审团成员的声明

QUESTION STH 质疑某事, to refuse to accept that something is right, fair, or legal

质疑〔某事的正确性、合法性等〕，对…表示怀疑:

a boy with a reputation for challenging the authority of his teachers

一个以挑战老师权威而出名的男孩

Viewpoints such as these are strongly challenged by environmentalists.

类似这样的观点遭到环境保护主义者的强烈质疑。

They went to the High Court to challenge the decision.

他们就这项判决向高等法院提出上诉。

Dr. Carver to deny his involvement!

我质疑卡弗医生是否敢否认自己和这事无关！

COMPETITION 竞争, to invite someone to compete or fight against you, or to try to win something

向…挑战; 邀请〔某人〕比赛;

After lunch Carey challenged me to a game of tennis.

午饭后，凯里邀请我进行一场网球比赛。

Liverpool are challenging for the title (=in a position where they could win).

利物浦队要挑战冠军。

STH DIFFICULT 困难的事, to test the skills or abilities of someone or something

考验…的技术（能力）; 激发; 激励;

I'm really at my best when I'm challenged.

我遇到挑战的时候状态最好。

Every teacher ought to be challenging kids to think about current issues.

每一位老师都应激励学生思考当前的问题。

STOP SB 使某人停下, to stop someone and demand proof of who they are, and an explanation of what they are doing

喝停盘问〔某人的身份、意图等〕:

We were challenged by the security guard at the gate.

我们在门口被保安人员拦住查问。

IN LAW 法律方面, [law] to state before the start of a COURT case that a juror is not acceptable

〔开审前〕对〔某陪审员〕表示反对

Lewis is his main challenger for the world title.

刘易斯是他夺取世界冠军头衔的最大挑战者。