重點解釋：
knock down
英[n?k daun] 美[nɑk da?n]
[詞典] 拆卸; <非正>擊倒; 拒絕; <非正>降價;
[例句]He died in hospital after being knocked down by a car
他被車撞倒後死在了醫院。
The market might abandon the stock, and knock down its price
市場可能會拋售該股票，從而令其股價下跌。
A drunk driver knocked down and killed two girls
壹個酒後駕駛的司機撞死了兩個女孩兒。
They have since knocked down the shack.
從那以後他們拆掉了簡陋的棚屋。
It manages to knock rents down to$ 1 per square foot.
成功地將租金降到每平方英尺1美元。