You examine an archeological site thought to be from the earliest settlement of humans in America. You measure the ratio carbon-14/carbon-12 from an artifact at the site and obtain 0.2 parts per trillion. Currently in the atmosphere, this ratio is 1.3 parts per trillion. How long ago do you predict that humans settled America?

a. 36000 years ago
b. 15500 years ago
c. 6250 years ago
d. 6750 years ago
e. 22500 years ago
f. 1280 years ago

How does an island of development promote economic development? a. islands of development contribute to mining industries because they continue to form mountains.b. islands of development have been ruled by dictators since the 1950s as part of an economicexperiment.c. islands of development promote international development by creating new islands.d. islands of development stimulate job creation in underdeveloped nations. select the best answer from the choices provided.0 000

Which of the following is a characteristic differentiating tropical and temperate rainforests? a. the location b. the types of trees c. the average temperature d. all of the answers are correct

Along with timber, what is a common export harvested from southeast asia?