knock down . knock to the floor  . knock to the ground击倒；击败

He knocked his opponent down．他击败了对手。

With one blow he knocked his assailant down．他一拳就把袭击他的人打倒在地。

knock down . strike and cause to fall撞倒

The girl was knocked down by a lorry as she ran across the road．这女孩在跑过马路时被卡车撞倒了。

He was knocked down by a car and was rushed to the hospital．他被汽车撞倒后，随即被送进医院。

knock down . signify the sale of an article at auction by a blow of the hammer 拍卖时击槌以示卖出

The picture was knocked down to me for twenty dollars at an auction．这幅画在拍卖中以二十美元卖给了我。

The auctioneer knocked the bureau down to a furniture dealer from York．拍卖人把那张写字台卖给约克的一个家俱商。

A mahogany table was knocked down for five pounds．一张桃花心木桌以五英镑的价钱卖出去了。

knock down . compel somebody  to lower the price of 迫使减价；压价

He asked five hundred dollars for his car， but I managed to knock him down by ten percent．他出价五百美元卖他的车子，但我竭力使他减价百分之十。

The price was knocked down to five pounds．价格降低到了五镑。

The storekeeper decided to knock down his remaining winter stock．店主决定将剩余的冬季存货减价出售。

knock down . take apart in handling or transportation拆散；拆零（以便装运）

London Bridge was knocked down stone by stone and rebuilt in the middle of a desert in the United States．伦敦大桥被一块石头一块石头地拆除了，重新安装在美国的一片沙漠中心。

We knocked down the bookcase and packed them in the car．我们将书橱拆散装进汽车。

knock down . tear down； demolish拆毁；拆除

These old houses will be knocked down to make room for a stadium．这些旧房子将被拆除，以腾出地方来造一座体育馆。

We are going to knock down those old buildings．我们不久就要拆除那些旧建筑物。

knock down . embezzle money from one's employer盗用雇主之钱

He knocked down plenty of the cash without being caught．他盗用了不少现金，未被发觉。

knock down . receive，as a salary or a scholastic grade； earn挣得（薪金）；获得（分数）

He knocks down about twelve thousand dollar a year．他一年大约赚一万二千美元。

knock down . call upon要求

The chairman knocked her down for a song．主席要求她唱一支歌。

knock down . cause（a sailing vessel） to heel，as by a gust of wind，to such a degree that it cannot right itself （风）使船倾斜

Lower the sail or the boat will be knocked down．把帆放下来，否则船会被风吹翻的。

knock off . stop；leave work 中止（工作）；停工

Let's knock off early today and go to see a ball game．我们今天早点下班去看球赛。

We start work at eight and knock off at twelve．我们八点开始工作，十二点收工。

What time do you knock off on Fridays? 你们星期五什么时候下班?

knock off . deduct除去；扣去；减去

He knocked off ten percent from the price．他杀价百分之十。

When he received his money he found that five pounds had been knocked off for expenses incurred．当他收到钱时，他发现由于各种开支扣除了五镑。

knock off .compose（a poem， an article， a novel，） rapidly and in a short time很快就写出（诗、文章、小说等）

He sat down and knocked off an article for the local paper in an hour．他坐下来在一小时内很快就给当地报纸写了一篇文章。

She knocked that article off in no time at all．那篇文章她一挥而就。

The boy knocked off his homework in fifteen minutes and ran out to play tennis．这孩子在十五分钟内匆匆写完作业就跑出去打网球了。

knock off . steal from； commit robbery at 偷窃；抢劫

They knocked off a bank．他们抢了一家银行。

The boy knocked off a necklace when the shop assistant wasn't looking．那个男孩在店员不注意时，偷了一条金项链。

knock off . eat up quickly吃得快

He knocked off two chops and a plateful of vegetables in about ten minutes and then asked for more．他在十分钟内就吃完两块排骨和一碟蔬菜，然后又要加菜。

knock off .obtain获得

He knocked off a Nobel prize．他获得了诺贝尔奖金。

knock off . take into custody； arrest拘留；逮捕

He was knocked off by the police．他被警察拘捕了。

knock off . murder谋杀

The gangsters knocked off Herman．歹徒谋害了海尔曼。

They say that the policeman got knocked off because he saw the raiders'faces．他们说那个警察被杀死了，因为他看见了强盗的面孔。

knock off somebody 's feet . surprise somebody  so much that he does not know what to do使人惊慌失措

When Charlie was given the prize，it knocked him off his feet．当向查理授奖时，他不知所措。

knock on . continue working继续工作

Let's knock on for another．让我们再干一个小时吧。