X. Read the passage and answer the questions. KEEPING OUR TEETH HEALTHY It‟s ver…
X. Read the passage and answer the questions. KEEPING OUR TEETH HEALTHY It‟s very important to have healthy teeth. Good teeth help us chew our food. They also help us 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 … Đọc tiếp