perplexed 形容词 adj.
因不能理解某事而困惑、糊涂的
Gary looked rather perplexed.
加里看起来相当困惑.
I am perplexed to know what to do.
我不知道怎么做才好.
可做前置定语：a perplexed expression/look/voice困惑的表情、眼神、声音
puzzled 形容词 adj.
因不能理解某事或某事的原因而困惑的,搞糊涂的,茫然的
beginning to get a bit puzzled
开始变得有点困惑
Everyone was a bit puzzled by her sudden departure.
每个人都对她的突然离开有点儿困惑不解.
可做前置定语：a puzzled look困惑的表情
at a loss
1.不知所措
He found himself at a loss for words of consolation.
他简直想不出安慰的话来.
Mary is at a loss what to do next.
玛丽不知道下一步该做什么.
2.亏本
They must sell the goods at a loss.
他们必须亏本出售商品.
我们最常用的表示“困惑”这个意思的词是puzzled和confused,偏重口语中使用perplexed稍微少见一些,侧重书面语,但口语也可使用