Where do plants get nitrogen mainly 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.

The united states uses which source of energy to produce almost 40 percent of its electricity

The part of the eye that closes and opens to let light in is .