How long has he worked in the radio studio? Can you tell me.合并成宾语从句

问题描述:

How long has he worked in the radio studio? Can you tell me.合并成宾语从句
是he had worked 还是he has worked说明一下理由

Can you tell me how long he has worked in the radio studio?
因为主句 can tell 是一般现在时