switching, in accordance with a request from a user who uses said information related to state of degradation, said information to be displayed to said user to {HEAD ~ any} of {TAIL ~ said first to third display items} 
of
switching , in accordance with a request from a user who uses said information related to state of degradation , said information to be displayed to said user to { HEAD ~ any } of { TAIL ~ said first to third display items }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL