Q: Billions of what inside the human digestive tract help us digest food, make vitamins and play other important roles?


Read this paragraph and choose the correct option from the provided answers:

There are billions of bacteria inside the human digestive tract. They help us digest food. They also make vitamins and play other important roles. We use bacteria in many other ways as well. For example, we use them to:.

 Choices:

- neurons

- viruses

- red blood cells

- bacteria


A:
bacteria