Which environmental factors would most affect the populations of developing countries

Providing immunity by injecting the body with a weakened form a pathogen is known as

Will someone me with this.. specialized cells which perform a particular function form: tissues organs or organism

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.