tap ，knock ，hit有什么区别啊？

tap1
KK: []
DJ: []
vt.
1. 轻拍,轻叩,轻敲
He tapped me on the shoulder.
她轻轻地拍拍我的肩。
2. 轻轻敲出(或敲掉)[O]
He tapped the ashes out of his pipe.
他轻轻地将烟斗里的烟灰敲出来。
3. 补鞋底
4. 【美】指定,选定
Mr. Smith was tapped for police commissioner.
史密斯先生被指定为警察局长。
vi.
1. 轻拍,轻叩,轻敲[(+on)]
Listen! Someone is tapping on the window.
听!有人在敲窗户。
n.[C]
1. 轻拍,轻叩,轻敲
There was a tap on the window.
有人在轻叩窗户。
2. 鞋掌;鞋底
tap2
KK: []
DJ: []
n.[C]
1. 龙头,阀门
He left the tap open to fill the kitchen sink with water.
他将水龙头开着让厨房的水槽注满水。
2. (酒桶等的)塞子,栓子
3. (电流)分接头
4. (电话)搭线窃听;窃听器
They put a tap on his telephone and recorded all his calls.
他们在他的电话上装上了窃听器,录下了所有通话。
5. 【医】(为抽液而作的)穿刺
vt.
1. 装上塞子(嘴子)
They tapped a barrel of beer.
他们打开桶塞放出啤酒。
2. 在(树)上刻痕取液
They worked on the farm, tapping rubber trees.
他们在这农场做割胶的工作。
3. 接通(总电源,总水源等)
They tapp