Context and question: Agriculture is dominated by the cultivation and sale of food crops such as cassava, peanuts, maize, sorghum, millet, sesame, and plantain. The annual real GDP growth rate is just above 3%. The importance of food crops over exported cash crops is indicated by the fact that the total production of cassava, the staple food of most Central Africans, ranges between 200,000 and 300,000 tonnes a year, while the production of cotton, the principal exported cash crop, ranges from 25,000 to 45,000 tonnes a year. Food crops are not exported in large quantities, but still constitute the principal cash crops of the country, because Central Africans derive far more income from the periodic sale of surplus food crops than from exported cash crops such as cotton or coffee.[citation needed] Much of the country is self-sufficient in food crops; however, livestock development is hindered by the presence of the tsetse fly.[citation needed]
What kind of exported cash crops dominate agriculture?
Answer: unanswerable
Context and question: Modern chemistry emerged from the sixteenth through the eighteenth centuries through the material practices and theories promoted by alchemy, medicine, manufacturing and mining. A decisive moment came when 'chymistry' was distinguished from alchemy by Robert Boyle in his work The Sceptical Chymist, in 1661; although the alchemical tradition continued for some time after his work. Other important steps included the gravimetric experimental practices of medical chemists like William Cullen, Joseph Black, Torbern Bergman and Pierre Macquer and through the work of Antoine Lavoisier (Father of Modern Chemistry) on oxygen and the law of conservation of mass, which refuted phlogiston theory. The theory that all matter is made of atoms, which are the smallest constituents of matter that cannot be broken down without losing the basic chemical and physical properties of that matter, was provided by John Dalton in 1803, although the question took a hundred years to settle as proven. Dalton also formulated the law of mass relationships. In 1869, Dmitri Mendeleev composed his periodic table of elements on the basis of Dalton's discoveries.
When did modern chemistry come into existence?
Answer: the sixteenth through the eighteenth centuries
Context and question: The expansive area northwest of the city limits is diverse, ranging from the rural communities of Catalina and parts of the town of Marana, the small suburb of Picture Rocks, the affluent town of Oro Valley in the western foothills of the Santa Catalina Mountains, and residential areas in the northeastern foothills of the Tucson Mountains. Continental Ranch (Marana), Dove Mountain (Marana), and Rancho Vistoso (Oro Valley) are all masterplanned communities located in the Northwest, where thousands of residents live.
Which town is Rancho Vistoso located?
Answer:
Oro Valley