Which statement is true about star a? it is red in color. it is yellow in color. it is four times brighter than the sun. it is four times dimmer than the sun.

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.

Why are current extinctions of concern to enviromentalists?

Explain why it’s important for scientists to study the sun. list at least two challenges researchers face when examining earth’s nearest star.