GIÚP MK BÀI NÀY VỚI MK CẦN GẤP LẮM Read the following passage and mark the letter A, B, C or D to indicate the correct answer to each of the questions. It is very important to have healthy teeth. Good teeth help us to chew our food. They also help us to look nice. How does a tooth go bad? The decay begins in a little crack in the enamel covering of the tooth. This happens after germs and bits of food have collected there then the decay slowly spreads inside the tooth. Eventually, poison goes into the blood, and we may feel quite ill. How can we keep our teeth healthy? Firstly, we ought to visit our dentist twice a year. He can fill the small holes in our teeth before they destroy the teeth. He can examine our teeth to check that they are growing in the right way. Unfortunately, many people wait until they have toothache before they see a dentist. Secondly, we should brush our teeth with a toothbrush and fluoride toothpaste at least twice a day-once after breakfast and once before we go to bed. We can also use wooden toothpicks to clean between our teeth after a meal. Thirdly, we should eat food that is good for our teeth and our body:milk, cheese, fish, brown bread, potatoes, red rice, raw vegetables and fresh fruit. Chocolate, sweets, biscuits and cakes are bad, especially when we eat them between meals. They are harmful because they stick to our teeth and cause decay. 26. Good teeth help us to ______ . A. have good eyesight B. be important C. chew our food D. have good health 27. When food and germs collect in a small crack, our teeth______. A. send poison into the blood C. become hard B. begin to decay D. make us feel quite ill 28. A lot of people visit a dentist only when______ . A. they have well brushed teeth C. they have holes in their teeth B. they begin to have toothache D. their teeth grow properly 29 Sweets are harmful because they may make our teeth ______. A. crack B. decay C. painful D. black