Smiling increases blood flow and starts the production of "happy brain" chemicals.

微笑着增加血流量，并开始生产的“快乐大脑”的化学品。

youdao

Smiling increases blood flow and starts the production of "happy brain" chemicals.

微笑着增加血流量，并开始生产的“快乐大脑”的化学品。

youdao