a) a hospital
A hospital is the place where to go when you are in pain.
A hospital is the place where to go when you are in pain.

b) to improve
Eating healthy improves people's health.
Eating healthy improves people's health.

A healthy (health) lifestyle is crucial for humans. Unhealthy lifestyles are harmful
(to harm) for our bodies. One improvement
(to improve) is to eat meals that provide (to provide) enough vitamins and minerals. For example, drinks containing (to contain) too much sugar are the worst you can do to your body. Plenty of people eat because of boredom (bored), which is causing overweight. Their digestion(to digest) is oftentimes not functioning very well. An unhealthy lifestyle damages (to damage) the cells and our entire nervous system. If overweight people exercise (to exercise), their body will thank them in numerous ways. The doctor's recommendation (to recommend) is to exercise one hour per day.
Have you ever tasted (to taste) fresh vegetables and fruits? They are delicious!