John took his umbrella to be on the safe side.
约翰带上雨伞以防万一。
语言点：to be on the safe side的意思是to be safe; to be cautious; to be very well prepared，也就是“为了保险起见，以防万一”。
John took his umbrella to be on the safe side.
约翰带上雨伞以防万一。
语言点：to be on the safe side的意思是to be safe; to be cautious; to be very well prepared，也就是“为了保险起见，以防万一”。