感到困惑

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

那位教授从不会感到困惑，也不会被任何题所难倒。

The difficult problem present by him entangle the conferee.

他所提题使与会人士感到困惑。

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

他然更加感到困惑，因为这突一笑，使他感到莫名妙。