It shows your inconsistency. Every good student should be regular in studies and everything. You would be familiar with Edison. He was succeeded to invent bulb after thousand attempts. If he had given up somewhere then he wouldn’t be successful. Continue to work hard Inshallah it will repay you. The subject which you feel is week give more time to it. Make questions your self at home then give answer & get it checked by your father or mother. Then they will tell you the mistakes. Rectify them. Don’t become an average student but distinction.