Hi friends, I have a question: “elaborate” or “elaborate on”? Sometimes I saw people use “elaborate something”, for example, “Then we elaborated the concept of map generalization in mobile environment from the point of the fundamental problems in map generalization.”While sometimes I saw people use “elaborate on something “. For example, “Then it summarizes the main objectives of the whole system to be achieved, and elaborated on the general framework and system design.” Which one is correct? Thanks.