Answer:
I'm a food made of flour, water, and yeast or another leavening agent, mixed together and baked. You need me to make a sandwich.
What can be opened but cannot be closed?
What do you call bread that has been browned in a small electric oven until it is crispy?
A wonderful elixir, It is your fluid fixer. Gulp it down and turn like a concrete mixer. Dark as night and sweet as sin, It's like liquid heroin.
What is eaten by man, served among many, grown by many, and white as snow?
I stay where I am when I go off. What am I?