The circulatory system

Hemos aprendido qué es el aparato circulatorio y cómo funciona ....
Contesta a las siguientes preguntas:

1. What does the circulatory system do?
2. What does blood give our cells?
3. What are the three types of blood vessels?
4. What is the heart? How does it work?
5. How many times does blood pass through the heart?
6. How many times does the heart beat in a minute?