用适当的短语完成下列句子。 l. We should ____ ourselves ____ ____ drugs. 我们应该远离毒品。 2. You need more protein to ____ you ____. 你需要增加蛋白质以增强体质。 3. His actions could ____ ____ him losing his job. 他的行为有可能会导致他丢了工作。 4. He is trying to ____ the family's expenses. 他正尽力减少家庭开支。 5. If you ____ the sun's rays ____ dry wood with a burning-glass, it will start burning. 如果你用取火镜使太阳光线聚焦在干木头上，木头就会燃烧起来。