only when you smile at it will it smile back at you
只有当你对它微笑，它才会回以微笑。
该句使用条件结构表达行为与结果之间的对应关系。
"Do not wear sadness on your face or coldness on your lips."
"Life is like a mirror: smile at it, and it smiles back."
"Positive thinking leads to a positive life, while negative thinking results in a negative life."
"When feeling low, remind yourself to focus on what you have rather than what you lack."
"I have maintained a positive attitude during my time at college."