英语大神帮忙翻译一下 分析一下 谢谢啦

中文翻译：

笑可以减轻疼痛的原因似乎是，它可以帮助在大脑中产生一种降低压力和疼痛的化学物质。

第一级，表语从句：

主语：The reason why laughter can reduce pain 

系动词：seems to be 

表语（从句）：that it helps to produce a kind of chemicals in the brain which reduces both stress and pain.

that是表语从句的连词

对主语进行细分（定语从句）：

对表语进行细分（that是表语第一级的连词，不再进入这一级的划分）：

the reason why laughter can reduce pain seems to be that it helps to produce a kind of chemicals in the brain which reduces both stress and pain.
笑能够减少疼痛的原因似乎是它能帮助产生在大脑中产生一种化学物质，该物质能减轻压力和痛苦。
The reason why…… 意为“……的原因”
seems to be 意为“似乎是”
表语从句that it helps produce a kind of chemicals in the brain which reduces both stress and pain.
定语从句 which reduces both stress and pain.，修饰chemicals