the ap exam is in may for me and up until now, i havent really been paying attention or studying. i know almost nothing about world history. im now starting to pay attention and i wanted to know if i could get a 3 or 4 if i pay attention for the remaining topics and read a crash-course book on the other stuff i didnt pay attention on. like an ap world history crash course book. would this get me a 3 or 4 maybe? thanks!