Question

________ thousands of tiny projections that add even more surface area to villi​

Answer 1

Each villus, in turn, has thousands of even smaller projections called microvilli (singular: microvillus).

Step-by-step explanation:

The villi contain capillaries, which are tiny blood vessels. Nutrients are absorbed into these capillaries across the surfaces of the villi and microvilli. Because there are millions of these tiny projections, they greatly increase the surface area for absorption.