They are both important because mechanical has to do with physical - cause mechanical means physical, so chewing your mouth is physical (you break your food into smaller pieces physically). And then chemical digestion is when food and saliva mix together. They happen when breaking down food into nutrients - enzymes. Enzymes are important for that process, because they make a nutrient.
Hope this helps!!
The correct answer should be B. Small regions interspersed with other biomes. This type of a biome is found on all continents and in many countries. It's specific because it's similar to a desert when it comes to yearly precipitation, but it is different insofar that it has a lot of plants and animals that are mostly nocturnal predators.
