The Healthy Habits Survey (调查) shows that only about one third of American seniors have correct habi

C. four times a day D. eight times a day
3. Which of the following is TRUE according to the text?
A. We should keep from touching our faces.
B. There are less than 300 types of bacteria in the mouth.
C. A kitchen sponge can carry more germs than a toilet.
D. We should wash our hands before touching a door handle.

答案DDC