Final answer:
The items necessary for constructing a casket spray are flowers, floral foam, and ribbon.
Step-by-step explanation:
A casket spray is a flower arrangement that is placed on top of a casket during funeral services. The items necessary for constructing a casket spray are flowers, floral foam, and ribbon.
Flowers are the main component of a casket spray and are arranged in a way that covers the casket and provides a visually appealing display. Floral foam is used to hold the flowers in place and ensure they stay hydrated. Lastly, ribbon is used to add decorative accents and personal messages to the casket spray.