英语语法分析

Tax the marketing and sale of unhealthful foods.

给不健康食品的销售加税。

Oxygen plays a key role in metabolism, but can also be an unhealthful agent.

氧分在新陈代谢方面起着关键作用，但也是引起不健康的因素。

The unhealthful radioactivity in environment has increasingly been an interest problem.

环境中放射性对健康的影响日益成为人们关心的问题。