Please teach me! "There is no end of learning" "There is no end in learning There is no end on learning which one is correct, why?

PLEASE CORRECT During my master's degree, I have worked as a assistant for circuit course assistant for about two years. I cherish this opportunity very much. In order to explain the knowledge points in the most popular language and Help students think in different directions, I have referred to various of versions of the textbooks. For instance, I used to explain Power in this way: When we go to the swimming pool, we need to pay entrance fee and deposit. The entrance fee is consumed, just like Active Power. In contrast, deposit will be returned after the end of swimming as same of reactive power. And the then the total amount we pay is the right Power. Throughout the process, I not only successfully completed my work, but also organized and deepened my knowledge.