Which of the following can be used to determine the composition of a star? a. line spectra b. the star’s magnetic field c. light from sunspots d. blackbody spectrum

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.