to knock gently 敲轻轻 ; 轻轻敲门 ; 轻轻地敲门
Your competitor has built a 12" thick steel door between the customer and any source of value. Knock gently on the door.
你的对手却在客户和有价值信息之间建起了一道12英寸厚的铁门。
Voice: the choice of real wood of the doorkeeper thickness, still can knock gently pat face, voice, even if the door depressing the quality is good.
声音：选择实木门的时候可以看门的厚度，还可以用手轻敲门面，若声音均匀沉闷，则说明该门质量较好。
Knock the powder out of the tin gently.
从罐子里倒粉出来要轻点。
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