The fact that so many people still smoke          that we need a nationwide campaign _________ the awareness of the dangers of smoking.

    Replacing some things in your house at the right time can make you healthier. Some researches show us when and why the following things should be replaced.

Word Box: wool羊毛 dry-clean 干洗  bacteria 细菌

下列短语成语涉及到的知识与光的直线传播无关的是（　　）