knocked down撞到；拆装的；拍板成交；降低价格
knocked out喝醉；神志不清；被麻醉
1.England had been knocked out of the World Cup.
英格兰队已被淘汰出世界杯赛。
2.He died after being knocked down by a car.
他被一辆汽车撞倒后死了。
3.Just then, someone knocked at the front door.
就在那时，大门口有人敲门。
4.She knocked my drink flying.
她把我的饮料打翻了。
5.I knocked on the door but there was no response.
我敲了门，可是没有回应。
6.We have knocked 10% off admission prices.
我们已将入场票的价格降低了10%。