感到困惑

The difficult problem present by him entangle the conferee.

他所提出的问题人士感到困惑。

The professor is never at a nonplus, and never perplexed by a problem.

那位教授从来不感到困惑，也不被任何问题所难倒。

He was still more perplexed, for this inconsequent smile made nothing clear.

他然更加感到困惑，因为这突如其来的一笑，他感到莫名其妙。