So the web plays the glorious role of middle man.

所以，网络就成了有史以来最好的中间人。

A Mediator is literally a 'middle man', a go between.

的角色可以直译为「中间人」。

And the latest thinking is to improve yields still further by cutting out the middle man.

最新的想法是，通过省掉人类消化这一中间过程，进一步提高沼气生成率。

Someone to take charge, look at the bigger picture, act as the translator/middle man.

总要有人掌管全局，作为传话者/中间人吧。

Then the middle man then sells the trash to be dealt with and or separated and recycled.

在中国，人们会通过中间商以付费的方式收集可回收的垃圾，然后中间商再将垃圾卖掉或分类回收。