You can rely on him to respond to a challenge.

你可以信赖他，他懂得应付挑战。

《牛津词典》

I called out a challenge, but there was no reply.

我发起了一个挑战，但是没人回应。

《柯林斯英汉双解大词典》

Taking her with me on official occasions has been a challenge.

在正式场合带上她对我而言是一种挑战。

《柯林斯英汉双解大词典》

A challenge that affects parents, children and citizens in almost every community in America should not be a Democratic problem or a Republican problem.

VOA: special.2010.08.12

Let's see if we can do that, and it's a little bit of a challenge for the performer.

让我们看看能不能做到这个,对于表演者来说,还真是个挑战呢

耶鲁公开课 - 聆听音乐课程节选

Because it also means that every day we don't do something, we are not meeting a challenge.

因为这意味着,如果每天我们不去做些事情的话，我们所面临的挑战。

普林斯顿公开课 - 人性课程节选

After all, proving the death or injury of one person is enough of a challenge.

CNN: Peanut sentence sends a message

But Lanza sees his work as more than a challenge, or a call to arms.

FORBES: Sciences and Medicine

And that's a challenge to Scots' time-honoured sense of themselves, as the poor economic cousins.

BBC: No longer the poor relation