Why are sedimentary rocks more useful than metamorphic or igneous rocks in establishing the relative ages of rock?

Question#29: why does the tropical ocean have a greater temperature range than the temperate ocean?

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.

"your temperature analysis reveals a pattern with coldest temperatures located to the portion of the map."