??i v?i hình th?c n?p ti?n qua th??cào, ng??i ch?i c?n chu?n b??th??cào và ??m b?o th??còn h?n s??d?ng và ch?a s??d?ng qua l?n nào. Cheat-sheets of systems may be handy for beginners who want to start with a new technological innovation, or for authorities who would like to refresh their memory on some aspects. Cheatsheets of systems are av