Audio problems in process blocks

I have been uploading Mp3 files into each slide of my process block, but it only allows me to do one audio clip at a time. I will add audio for the Introduction, but then have to exit out of the block and go back into to editing to add audio the the next slide, so on so forth. It will not allow me to select the audio option at all. I was wondering if anyone else had this issue and if there was a reason for this, as it is incredibly annoying and time consuming