Rainwater contains hydrogen of a heavy form called deuterium. The deuterium content of wood reflects the deuterium content of rainwater available to trees during their growth. Wood from trees that grew between 16,000 and 24,000 years ago in North America contains significantly more deuterium than wood from trees growing today. But water trapped in several North American caves that formed during that same early period contains significantly less deuterium than rainwater in North America today. Which of the following, if true, most helps to reconcile the two findings?(A) There is little deuterium in the North American caves than the deuterium in the water trapped there.(B) Exposure to water after a tree has died does not change the deuterium content of the wood.(C) Industrialization in North America over the past 100 years has altered the deuterium content of rain.(D) Trees draw on shallow groundwater from rain that falls during their growth, whereas water trapped in caves may have fallen as rainwater thousands of years before the caves formed.(E) Wood with high deuterium content is no more likely to remain preserved for long periods than is wood with a low deuterium content.

1. in 1492, spain expelled after being under their rule for centuries. a. the portuguese b. the basques c. the castilians d. the moors 2. an important cultural center during the renaissance was the city of a. milan b. bologna c. florence d. naples 3. what is the connection between the minoan civilization and a volcanic eruption on thera? a. the earthquake happened a century before the collapse of the civilization. b. the earthquake created a graben. c. the earthquake caused the collapse of the civilization. d. the earthquake caused a volcanic eruption. 4. throughout history, other cultures influenced greece through a. military conquest b. shared ideals c. trade agreements 5. geographically, spain is isolated from the rest of europe by a. portugal b. the atlantic ocean c. the pyrenees mountains d. narrow coastal plains 6. most of central spain is known as the meseta, which is the spanish word for a. mountains b. plateau c. peninsula d. plains 7. for the people of ancient greece, the  iliad, and the  odyssey  a. copied western ideals b. were not popular c. presented community standards d. were children’s poems\ 8. western cultures got many of their ideas about from ancient greece. a. warfare b. democracy c. education d. agriculture 9. how is greece’s natural vegetation similar to that of other mediterranean countries? a. it has been damaged by forest fires. b. it is mainly deciduous forests. c. it grows rapidly in the wet climate. d. it has been reduced to scrub vegetation by overgrazing. 10. what is the most productive agricultural area in italy? a. the alps b. the po valley c. southern italy d. the apennines 11. many factories in northern italy use for energy. a. coal b. hydroelectricity c. nuclear energy d. natural gas 12. what major landform covers much of italy? a. the apennines b. the po river valley c. the alps