____，听唱新翻杨柳枝。（刘禹锡《杨柳枝词》）
The findings support another study which showed that being happy ______ reduce the risk of heart disease.
在追寻科学家研究足迹的过程中，某同学为探究恒力做功和物体动能变化间的关系，采用了如图1所示的实验装置．
