短语词组短语slack -off weight 下放时钻具重量slack k off 滞销Slack off the sail 把帆放松Slack Off A Little 放松一点Don T Slack Off 不要偷懒to slack off 松懈slack off weaken 由强转弱slack off in study 学习松懈slack off test 慢钻试验 返回 slack off