Read this passage, which was written by a spanish explorer in the 1500s. this great city of [tenochtitlán] is situated in this salt lake . . there are four . . entrances to the city, all of which are formed by artificial [walkways] . . the city is as large as seville or cordova; its streets . . are very wide and straight . . all the streets at intervals have openings, through which the water flows . . and at these openings, some of which are very wide, there are also very wide bridges, composed of large pieces of timber, of great strength and well put together; on many of these bridges ten horses can go abreast. this quotation describes