No learning can take place unless you understand what you read or jot down. If it is a new information, ask for clarification. If there are new words, always check them out. Substitute the meaning and then re-read the sentence. Or if something already familiar is written or said in a different or new way, always bother to research or ask the teacher or anouther authority. Never, never be indifferent to what you do not know or understand or what you are not sure of. Do not be content until you learn what you do not know. Develop a scientifically curious mind that always seeks to know and to understand facts. This is one of the secrets of effective studying and of successful students.