Which statement best describes the purpose of earth's spheres? they work together as open systems to cycle matter through ecosystems. they work independently as closed systems to cycle matter through ecosystems. they work together as open systems to move matter to living and nonliving parts of earth. they work independently as closed systems to move nutrients to living and nonliving parts of earth.

What was one step that charlemagne took to unite his kingdom? a. he chose a single strong heir to inherit his throne. b. he drove muslim forces out of europe. c. he created and supported schools. d. he declared himself head of the catholic church.

Arecession is the total value of all goods produced in a country in a given year total value of all goods and services produced in a country in a given year total amount of money earned in a nation over a specific period of time none of the answers are correct.

Which of the following describes an effect of globalization? a. car parts are manufactured in asia. b. an american company has factories in mexico. c. diamonds and other gems are sold in africa. d. china has placed restrictions on burning coal. drag the descriptions of developing and developed countries to the appropriate boxes. high income low income economy based on manufacturing economy based on services and finance widespread access to healthcare high poverty rates developing(box) developed (box) what is one development in medicine that has occurred because of new surgical techniques? a. more people die during long surgical procedures. b. transplants of organs have become more common. c. fewer people are opting for major surgeries. d. too many people are attending school to become surgeons. what most likely caused the condition shown in this photograph? a. overpopulation b. deforestation c. high carbon dioxide levels d. competition for water which of the following has occurred because of increased competition for resources? a. increased dependence on fossil fuels b. overproduction of coal c. water shortages d. overdependence on solar power what invention led to the development of smaller computers after the 1960s? a. the electronic circuit board b. the internet c. email d. the calculator