【例句】Instead of working at her lessons, Mary spends her time building castles in the air.【误解】玛丽不做功课，却花时间在空中造城堡。

【正确】玛丽不做功课，却花时间想入非非。

【说明】build castles in the air是习语，意思是“想入非非”、“空中楼阁”。