In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.

[Q]: Red blood cells (RBCs), also called erythrocytes, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O) to the body tissues -- via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the body's capillaries.
[A]: where do you find red blood cells in the body


[Q]: San Pedro River is a northward-flowing stream originating about 10 miles (16 km) south of the international border south of Sierra Vista, Arizona, in Cananea Municipality, Sonora, Mexico. The river starts at the confluence of other streams (Las Nutrias and El Sauz) just east of Sauceda, Cananea. Within Arizona, the river flows 140 miles (230 km) north through Cochise County, Pima County, Graham County, and Pinal County to its confluence with the Gila River, at Winkelman, Arizona. It is the last major, free-flowing undammed river in the American Southwest, it is of major ecological importance as it hosts two-thirds of the avian diversity in the United States, including 100 species of breeding birds and 300 species of migrating birds.
[A]: where does the san pedro river start and end


[Q]: This era, called the Jacksonian Era (or Second Party System) by historians and political scientists, lasted roughly from Jackson's 1828 election as president until slavery became the dominant issue in 1854 and the American Civil War dramatically reshaped American politics. It emerged when the long-dominant Democratic-Republican Party became factionalized around 1824. Jackson's supporters began to form the modern Democratic Party and rivals John Quincy Adams and Henry Clay, created the National Republican Party, which would soon combine with other anti-Jackson elements to form the Whig Party.
[A]:
when did the era of jacksonian democracy begin