关于 free，免费、自由、还是禁止？


free
免费 The beverage is for free in a buffet restaurant.
自由 You are free to do anything you want.
免于 Let’s go shopping in a duty-free store.


smoke-free = no smoking！
不是可以自由吸烟，更不是吸烟是免费的
而是禁止吸烟的

例句：
It is important that our staff can work in a smoke-free area.

The majorities want to work in a smoke-free zone when at work.

Smoke-free laws can reduce a major effect of tobacco smoking - heart disease.


其它词组：
toxic-free 无毒的
Duty-free store 免税店（出口/入口税）
Tax-free shopping 可退税的购物（消费税）