As an additional safeguard against weeds you can always use an underlay of heavy duty polyethylene.

作为另外一种预防杂草的防护措施，你可以一直使用一层厚重耐磨的聚乙烯底垫。

A system like ours lacks adequate safeguards for civil liberties.

在我们这样的制度体系中，缺乏有效保护公民自由的条款。

They will press for international action to safeguard the ozone layer.

他们将竭力要求国际行动来保护臭氧层。

They are taking precautionary measures to safeguard their forces from the effects of chemical weapons.

他们正在采取预防措施保护其军队免受化学武器的影响。