Which could be the impact of dental caries?

Which could be the impact of dental caries? () A. Pain B. Swelling C. Lost of school days D. All of the above * 47.Which of the sentences below is a false statement for tooth-brushing(AI? Tooth-brushing once daily is recommended B. Brushing for 2-3min per time C. Changing tooth-brushing every 2-3 mouths D. All of the above * 48.Which of the following method belongs to the primary prevention for dental caries?