Camp is related to Lake. Lake is related to Feature. Feature is related to River. you are likely to find Water in/at/on River. 
Concert is related to Serious. Serious is the opposite of Play. Computer can be used for Play. you are likely to find Computer in/at/on Demonstration. 
Camp <--RelatedTo--> Lake <--RelatedTo--> Feature <--RelatedTo--> River <--AtLocation-- Water 
Concert <--RelatedTo--> Serious <--Antonym--> Play <--UsedFor-- Computer --AtLocation--> Demonstration 