Excellent is related to Best. Best is related to Pet. Pet is related to Home. you are likely to find Wheelchair in/at/on Home. 
Invitation is related to Envelope. Envelope can be used for Protect. 
Excellent <--RelatedTo--> Best <--RelatedTo--> Pet <--RelatedTo--> Home <--AtLocation-- Wheelchair 
Invitation <--RelatedTo--> Envelope --UsedFor--> Protect 