1 . Perhaps the best example is shown by UNESCO, ________________ (这个组织运作一个阻止……的项目，两个定语从句) world cultural heritage sites around the world from disappearing. (根据汉语提示完成句子)

2 . Perhaps the best example is shown by UNESCO, which ________ that prevents world cultural heritages sites around the world from disappearing. (根据句意填空)