a. 惊讶不止的, 不知所措的

[ adj ]
filled with bewilderment
<adj.all>
at a loss to understand those remarkspuzzled that she left without saying goodbye

Nonplus \Non"plus`\, v. t. [imp. & p. p. {Nonplused}or
{Nonplussed}; p. pr. & vb. n. {Nonplusing} or {Nonplussing}.]
To puzzle; to confound; to perplex; to cause to stop by
embarrassment.

He has been nonplused by Mr. Dry's desiring him to tell
what it was that he endeavored to prove. --Spectator.