▲challenge由“挑战”引申出“要求，怂恿，唆使，激发，鞭策，促使”等几种意思，可以接复合宾语，由不定式充当宾补，宾语是其逻辑主语。例如：

The value of this exercise is that it challenges the students to express themselves freely.

这项练习的价值在于它能促使学生自由地表达自己的思想。

Never challenge a fool to do wrong. 不要怂恿愚人干错事。

I challenged him to show his proof. 我要求他拿出证据。

He challenged me to jump across the stream. 他用话激我跳过那条小溪。

The new position challenged him to study still harder during his spare time. 那个新职位激发他在业余时间更加努力学习。

▲如果不定式的动作是由句子主语发出的，那么，可以考虑不定式也是宾语之一。例如：

He challenged me to play another tennis game. 他向我挑战，跟他再打一场网球。

He challenged Lincoln to fight a duel. 他向林肯挑战，打一场决斗。

（Lincoln和 to fight a duel都是宾语，像promise sb. to do sth.一样）