Please help me, I've been stuck all day.

Ais a group of individuals of the same that exist together in the same place at the same time

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from

Many organizations release indexes used to measure the development of the world's countries. as we learned in this lesson, these indexes measure many factors, from life expectancy to happiness. in your opinion, what are the three most important factors we can use to determine how developed a country might be? explain your answers in a few sentences.