The tool is not a knowleadge is a ways how to find the knowleadge ,because we can not have teacher all the time , techer needs to teach 60 student ,how to care with each student , I know one things is you need to follow  to be a good student you must get a good score otherwise you are rubbish and firure ,the teacher says not me. So in this ways, the tool will be doesn’t work but study subject is only way to get a high score. Again is Education system crash to make this result.