Challenge - In this case, the server authentication follows a challenge-response dialog.

Challenge——在本例中，服务器身份验证采用询问-响应对话。

youdao

There is a kind of relation of "challenge-response" between public crisis and governance mode.

公共危机与治理模式之间构成了一种“挑战—回应”的循环关系。

youdao

A CAPTCHA is a challenge-response test to determine that the response is not generated by a computer.

—一个验证码是质问-响应的测试以便于确定这个响应是不是被一个计算机产生的。

youdao

"The challenge right now is that our emergency pre-positioned supplies were running quite low because the response in West Java was in progress still and that quake had just happened a few weeks ago,"

VOA: standard.2009.10.01

The natural challenge-response we all have in us is what will be the biggest help to the new amputees.

CNN: Amputees never say 'I can't'

Finally, the BP spill has presented an unprecedented challenge as an emergency environmental response and a long-term restoration effort.

WHITEHOUSE: Blog Action Day: Protecting America��s Waters Today

Caldwell was red carded following a 56th-minute challenge on Manchester City striker Carlos Tevez when the score was 0-0, provoking an angry response from Martinez, who believed his player should never have been sent off.

BBC: Wigan boss Roberto Martinez fined over referee comments