Private schools can take more exams (as long as the time does not coincide), and public schools can only apply for one in the morning, evening and evening. In addition, the reason why the country can only apply for one exam is not only the examination time. You must use センター for the national public examination. When you fill in the registration form, you will be asked to post a piece of paper cut from the plane ticket of センター (although it was not reported in the interim, it should be posted before and after) and then get it. Private enterprises that use センター also need pieces of paper, but on the one hand, there are many pieces of paper, on the other hand, they will not report to private enterprises that use センター so much (direct examination feels more common), so it is enough. So, unless you can easily get through the most difficult early stage, you have to think about which country you want to apply for (insurance or hard work). Of course, you can also apply for a guarantee later, but you can't get into college later.