短语词组短語on n and off 斷斷續續地;有時on shell and off shell 在殼和離殼on again and off again 分分郃郃switch on -and off 開關通斷on -and off-balance sheet 表內和表外項目switch on and off 開關通斷Handset On and Off 關機和待機時 返回 on and off