Will 提到了三个都带有“重要的”含义的形容词。你分得清楚哪个意思是“必须的”?哪个是“有相当一部分”?哪个是最常用的?

　　试试你能不能用标题中的三个单词完成这段文章：

　　The Department of Health issued an _____________ announcement that all hospitals must implement thorough cleaning strategy. It's _________ that the procedures must be followed to ensure ___________ reduction in cross infections.

　　答案就在节目录音里。