tap
单词辨析：
指用手指等轻叩、轻拍或轻敲，意在引人注意，或表示爱抚等情感。
He tapped me on the back.
他轻轻地拍了拍我的后背。
She tapped the table with her fingers.
她用手指敲打桌子。
He tapped his forehead knowingly.
他会心地拍了拍前额。
指用手掌、拳头或硬物用力敲打，以引起他人的注意或重视。
Please knock before you enter.
进来前请先敲门。
He wondered whether it would be proper to knock at her door.
他不知道敲她的门是否恰当。
I heard him knock his pipe out on the mantelpiece.
我听见他在壁炉架上磕打烟斗。
指用指关节、笔等快速轻敲或急拍，意在引人注意或表示某种情感。
The chairman rapped on the table for order.
主席敲桌子要求听众安静。
Angrily, she rapped on his window.
她生气地敲他的窗户。
He would rap his fingers on the desk when he had difficulty working out a math problem.
他做数学题遇到困难时总是要敲书桌。
相关例句：
Do not overexert when reaming holes or threading, lest breaking off the reamer or the tap.
铰孔或攻丝时，不要用力过猛，以免折断铰刀或丝锥。
When water is used this must be distilled water or spring water; never tap water.
用水的时候必须是蒸馏水或泉水，绝不能用自来水。
The advantage of group holidays is company on tap but time alone if you want it.
团体度假的好处在于，要找人陪伴非常容易，想要独处也行。
Tap your cheeks all over with the pads of your fingers.
用手指头肚儿轻拍脸颊一遍。
He assured MPs that ministers and MPs were not subjected to phone taps.
他向议员们保证，部长和议员的电话不会遭到窃听。
He owes his election to having tapped deep public disillusion with professional politicians
他将自己的当选归因于充分利用了公众对于职业政治家们不再抱希望的心情。