H2 is a molecule, but h20 is a

What protects the lining of the stomach from acidic gastric juices?

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

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