Mollusks are invertebrates such as the common snail.
Invertebrates are animals who lack a backbone or spinal column.
Mollusks are animals who lack a backbone or spinal column.
What does an animal like a mollusk lack that many other animals have?

* sensory neurons
* Energy.
* Bodily water
* kinetic energy
* alveoli
* the skin
* an organism's body
* spinal column