What is the purpose of having a water-tight covering?

Which of the following best describes the purpose of technology?

Glucose is a form of sugar found in the blood cells use glucose as a source of energy, but too much or too little can cause serious health issues so, the body uses the hormone insulin to regulate glucose n the blood insulin maintain glucose levels in the blood if blood glucose lovels got very high, what would you expect to see happen to insulin levels?

What best describes the structure of the declaration of independence?