1. The surface of the crown of the tooth is covered with a strong protective layer known as the _______.   enamel   dentine   cavity   root   Hint Half-n-half Clue   2. Which is the largest organ in the human body?   liver   pancreas   large intestine   small intestine   Half-n-half Clue   3. Which of the following is the common passage for the food eaten and the air breathed?   trachea   larynx   esophagus   pharynx   Half-n-half Clue   4. The part of the tooth outside the socket of the jaw is known as the crown.   True   False   5. Which of the following prevents food from entering the trachea (wind pipe)?   larynx   pharynx   glottis   epiglottis   Half-n-half Clue   6. Which is not a part of the large intestine?   ileum   colon   rectum   caecum   Half-n-half Clue   7. How many teeth does an adult human being normally have?   16   20   30   32   Half-n-half Clue