Something about sleep The situation：
    ※Most Americans slept under（1）

hours by 1975 and only around 7 hours in 2002.
    The facts：
    ※A（n） （2）

scientist believes that people's sleep needs to be different.
    ※Other scientists are looking for ways to （3）

a sleepy body.
    The meaning：
    ※The speaker thinks the study might make a difference to our（4）

.
    ※If we need less sleep，we'll have more time to（5）

，read，volunteer （做志愿工作） ，and spend time with family.