1:B The teacher has explained the commutative property, which is one of the properties of real numbers.
2:B The annexation of Texas spurred Americans to envision a nation that spread from coast to coast. By entering the union as a slave state, Texas contributed to the westward expansion of slavery. The Monroe Doctrine concerned European intervention in the Western Hemisphere. Mexican resentment of the Texas annexation was a major contributing factor in the Mexican War, which began the following year.
3:A Checks and balances prevent any branch of the government from running roughshod over the other two. Separation of powers refers to the distribution of specific powers among the three branches of government. Judicial review is the power of the courts to overturn legislative or executive acts that are deemed unconstitutional. Advice and consent is the power granted to the Senate to advise the President, ratify treaties, and confirm nominations.
4:D Organized by Lucretia Mott and Elizabeth Cady Stanton, the Seneca Falls Convention approved a Declaration of Sentiments that proclaimed the equality of men and women. The American Temperance Society was established in Boston in 1826. The Republican Party had its first official meeting in Jackson, Michigan, in 1854. The first antislavery society in America was founded in Philadelphia in 1775.
5:D The taiga, or boreal forest, is found only in the North Temperate Zone between the tundra and the steppes. The largest biome on land, it is characterized by coniferous forests and stretches across the northern regions of North America and Eurasia. Deserts, savannas, and tropical rainforests are all found at lower latitudes within the Torrid Zone.