The main cause of inadequate ammonia clearance at severe hepatic dysfunction is ( ) A: Impairment of glutamine synthesis B: Impairment of urea synthesis C: Impairment of acetylcholine synthesis D: Impairment of glutamic acid synthesis E: Impairment of γ-aminobutyric acid synthesis

Moisture in food can be divided into "bound water" and "free water" according to different properties. Which of the following is not bound water? A: The first layer of water molecules adsorbed to glucose molecules B: Water molecules with unpaired electrons entering the outer empty orbits of sodium ions C: Water molecules adsorbed in capillaries in food tissue D: Water molecules bound to the negative ion of glutamic acid on the protein peptide chain