folder, envelope, box, briefcase, filing cabinet, a safe, ...
because it holds papers together
flask
A picnic hamper.
That could be a gas tank or a gas can...
The name for a lavatory water container is a toilet tank. It is a reservoir that holds the water needed for flushing the toilet.
The container with the largest volume holds the most water.
Dewar flask
The amount a container holds is its capacity, measured in liters, gallons, or cubic meters.
you will need a gallon container.
A container holds volume.
No, a quart container holds 4 cups of milk, not just 1 cup.
Punnet