399. Companies could also reduce prices for those who stayed to eat food on their premises, offer money-off vouchers (中巴金券) or other incentives for those who returned packaging and put more bins at strategic points in local streets, not just outside their premises.
公司還可以給那些在經營場所用餐的消費者減價，為那些送回包裝的人提供代金券或其他鼓勵，同時在街道的關鍵位置放置更多的垃圾箱，而不僅僅是在他們的營業場所外。

六級詞匯講解:
本句的主干是Companies could also reduce..., offer...and put...who stayed to eat food on their premises和who returned packaging均為定語從句，修飾各自前面的those。premises意為“場所，經營場址”。如：

Beverages sold in this restaurant can only be drunk on the premises.
此餐廳的飲料只供堂飲。

reduce prices表示“減價”，money-off意為“減價，打折”，off本身也可表示這個意思，這時，其前面可以加打折的百分比。如：
All shirts have 10% off.
襯衫一律九折。

bin意為“（垃圾）箱”，垃圾箱也可以說dustbin或rubbish can。