be at a loss

• 茫然不知所措

be at a loss的用法和样例：

例句

1. He felt completely at sea in his new school.
   他在新学校中感到茫然不知所措。
2. When the saleswoman lost her job, she was at a loss what to do.
   当这位女推销员失去工作后，她茫然不知所措。