Why is the precambrian not divided into many time subdivisions whereas the paleozoic, mesozoic and cenozoic are?

What do most climatologists see as a major cause of rising global temperatures? a. earth's closer proximity to the sun due to its gravitational pull b. greenhouse gases produced by burning fossil fuels c. rising ocean levels caused by melting polar ice sheets d. water pollution cause by industrial waste

By the year 1900 new york city had more than just people of british heritage. there were more people of italian descent than the cities of florence, genoa and venice put together. it was home to more irish than dublin (the capital of ireland) and more germans than hamburg. joining them were many thousands of people of polish, hungarian, and czech descent. what term best describes new york cities changing culture? a a pot of chili b a bowl of sugar c a cup of coffee d a slice of cheese

As american population grew between 1820 and 1850, the percentage of americans living on farms also grew. a.true b.false