I'm all at sea; I've no idea how to repair cars. 我手足無措，不知道怎樣修理汽車。
The guide was ready enough with his usual pattern on the history of the place, but as soon as you began to question him on anything outside that, he was all at sea. 嚮導把該地歷史的老一套講得滾瓜爛熟，但當你一問起別的東西時，他就瞠目結舌，無言以對了。
I'm all at sea. 我一點主意也沒有。
My new hi-fi has so many lights and switches that I was all at sea when I first tried to use it. 我新買的那台高保真音響設備有許許多多指示燈和開關，以致我第一次打開它時竟不知所措。
