The passage of a bolus of food down the esophagus is assisted by what? MULTIPLE CHOICE.

A. Enzymes and acids

B. The lower esophageal sphincter

C. Peristalsis

D. The pyloric sphincter

Which one is an advantage of external fertilization a. the offspring are genetically identical to the parents b. more eggs can be fertilzed at one time c. more sperm can be released at one time d. more protection is available for developing plz