Chalk, egg shells, or snails should be powdered and added to the food to provide the calcium necessary for healthy shells.
(Chalk, egg shells, or snails; should be; powdered) (Chalk, egg shells, or snails; added; to the food; to provide the calcium necessary for healthy shells)
Chalk, egg shells, or snails Chalk, egg shells, or snails
should be added
powdered
to the food to provide the calcium necessary for healthy shells