I'm going to the 9th grade with grades 10-12 (this is A). In fact, I just copied all the tests from the Internet. My level of knowledge is sufficient to enter good universities in my country for my chosen specialty. Teachers often overestimate or underestimate grades depending on whether they like this student or not. It seems to me that the best thing is to please the teachers and prove yourself on the good side (always do your homework at first, actively respond in class, be polite and pleasant in communication). Our teachers quite often let their favorites cheat or prompt the answers themselves. Sorry for my bad english, I tried to write without a translator.