challenge

挑戰、難題、考驗

Learning a new language as an adult is a real challenge.

成年後學一種新語言是不小的挑戰。

質疑、異議

His theory has faced serious challenges from other researchers.

他的理論受到其他研究者強烈的質疑。

挑戰、邀戰

She accepted his challenge to a rematch next week.

她接受了他下週再比一場的挑戰。

質疑、對…提出異議

Several members challenged the accuracy of the report.

好幾位成員質疑那份報告的準確性。

向…挑戰、挑戰

The young player challenged the champion to a match.

那位年輕選手向冠軍下了比賽的挑戰書。