1. Oral cavity remains moist due to presence of a fluid known as _______.   Hint First letter clue   2. _______ is the opening in the body through which feces are excreted.   First letter clue   3. _______ is a muscular leaf-like structure helpful in swallowing of food and speaking.   First letter clue   4. Salivary glands secrete a fluid known as _______ which helps in digestion as well as in swallowing of food.   First letter clue   5. _______ is a tubular structure through which urine is excreted out of the body.   First letter clue   6. An average human adult has _______ teeth.   First letter clue   7. Heart lies on the left side of the _______ cavity.   First letter clue