The digestion of the food in humans begins in the mouth. In the mouth, the salivary amylase enzyme digests and breaks down a small amount of the starch present in the food. The digestion process begins right in the mouth. and continues till the intestine. The carbohydrates (starch) are the ones whose digestion starts in the mouth.
Hence, the blanks can be filled with 'mouth and amylase' respectively.
Gause's Competitive Exclusion Principle
The 'competitive exclusion principle' (CEP) states that two species with identical niches cannot coexist indefinitely. ... Gause helped propel ecology by his approach of experimentally testing mathematical models, and his unifying the concept of the niche with resource competition.