Viết ít nhất 150 từ trong khoảng 20 phút.
The line graph shows the acid level, or pH level, in the mouth after people eat fruit sugar, cane sugar and honey, over a period of 40 minutes.
Overall, all three foods made the mouth more acidic soon after eating, and then the pH level slowly went back to normal. Cane sugar made the mouth the most acidic for the longest time, while honey had the smallest effect.
At the moment the food was eaten, the pH level was 7 for all three. After 5 minutes, the pH level fell sharply. For cane sugar, it dropped to about 3.6, which was the most acidic level in the graph. For fruit sugar, it fell to about 4.2, and for honey it fell to about 4.8. All of these were below 5.5, which is the level where tooth decay happens.
After that, the pH levels increased again. Honey went back above 5.5 after about 14 minutes and reached 7 after about 25 minutes. Fruit sugar reached 5.5 at 20 minutes and returned to 7 at about 35 minutes. Cane sugar was the slowest. It stayed below 5.5 until about 32 minutes, and it only reached 7 after 40 minutes.