Plaque, a sticky layer of bacteria that forms on the tooth enamel, feeds on the sugars and starches from food particles in your mouth. This produces an acid that eats away at the enamel, causing weak areas and holes. Over time, the enamel breaks down, and a cavity forms.7 As the deca...
Bacteria in the plaque convert sugarinto acid that dissolves the tooth structure, causing holes or cavities. Because of these two contributing factors, dental caries has been described as a "diet bacterial" disease. The parts of teeth that are most vulnerable to tooth decay are areas where plaqu...
Cold sores come from a virus, and that virus can be shared by kissing, or by sharing eating utensils, or any other form of close contact between individuals. You may find over-the-counter creams and ointments helpful in easing the pain and discomfort they cause, and these treatments may al...
1. Does she have a headache? Yes, she does. / No, she doesn't. She doesn't have a headache. 2. Does George have an earache? Yes, he does. / No, he doesn't. George doesn't have an earache. 3. Do you have a toothache? Yes, I do. / No, I don't. I don't have a ...
题目一、单词辨音:选出画线部分读音与其他三个不同的单词()1.(a)call(b)tall(c)talk(d)all()2.(a)cold(b)old(c)phone(d)doctor()3.(a)mouth(b)house(c)how(d)month()4.(a)news(b)newspaper(c)must(d)stomach()5.(a)headache(b)head(c)medicine(d)meet()6.(a...