A/An, The or Nothing

This is a fill-in-the blank exercise.

They say an__ apple ___ day keeps _the_ doctor away, but I don't believe them. I like ____ bananas. I think _a__ banana __a__ day will do _a__ better job of keeping _the__ doctor away. _____ bananas are full of ___ good things. For example, eating _a__ banana before you exercise can give you enough energy for _a_ 90-minute workout. If you are anemic, you should know that ___ bananas are high in ___ iron. If you have ___ high blood pressure, eating_a__ banana will help regulate your ___ potassium. In fact, __the_ US Food and Drug Administration makes _the__ official claim that ____ fruit can help reduce __the_ risk of _a__ heart attack or stroke. If you are feeling down, eating ____ bananas can help that too! ____ bananas contain ____ tryptophan, __the_ type of protein that converts into ___ serotonin, _the__ "feel-good" chemical in the brain. Of course, ____ bananas are full of ____ fiber, which can help you control _the__ number of calories you consume and help regulate __the__ digestive system. So, I think _the__ saying should be, "_an__ apple and _a_ banana _a_ day will keep _the__ doctor away."
Suggerimenti:


Use:
"A" before general, singular noun phrases when the first word of the phrase starts with a consonant: a day; a banana; a 90-minute workout

"An" before general, singular noun phrases when the first word of the phrase starts with a vowel.

"Nothing" before general, plural noun phrases. You can use "some" in some cases.
"Nothing" before general noncount noun phrases: fiber; serotonin; tryptophan; good things; high blood pressure

"The" before specific countable and noncountable noun phrases: the digestive system; the doctor;  the saying; the number of calories; the risk of a heart attack or stroke