How do i use diatoms in a sentence

Many kangaroo rats live in the sonoran desert of the southwestern united states. they have a variety of adaptations for living in the desert. under which circumstance would the kangaroo rats of the sonoran desert be most likely to develop new adaptations by natural selection?

Someone me with this: a mineral' is determined by its actomic structure.

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above