What is a word made up of 4 letters yet is also made up of 3

Question: What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

Question: You are driving and you are hungry and thirsty.On the road you find 2 doors.1 has food and 1 has water(drinkable).:Question:What door do you open first????

Question: What tastes better than it smells?

Question: What goes in the water black and comes out red?

Question: What loses its head in the morning and gets it back at night?

Question: What two things can you never eat for breakfast?