Problem: Background: Carlos Santana  audio  (born July 20, 1947) is a Mexican and American musician who first became famous in the late 1960s and early 1970s with his band, Santana, which pioneered a fusion of rock and Latin American jazz. The band's sound featured his melodic, blues-based guitar lines set against Latin and African rhythms featuring percussion instruments such as timbales and congas not generally heard in rock music. Santana continued to work in these forms over the following decades. He experienced a resurgence of popularity and critical acclaim in the late 1990s.
Context: Carlos Santana's distinctive guitar tone is produced by PRS Santana signature guitars plugged into multiple amplifiers. The amps consist of a Mesa Boogie Mark I, Dumble Overdrive Reverb and more recently a Bludotone amplifier. Santana compares the tonal qualities of each amplifier to that of a singer producing head/nasal tones, chest tones, and belly tones. A three-way amp switcher is employed on Carlos's pedal board to enable him to switch between amps. Often the unique tones of each amplifier are blended together, complementing each other producing a richer tone.  He also put the "Boogie" in Mesa Boogie. Santana is credited with coining the popular Mesa amplifier name when he tried one and exclaimed, "That little thing really Boogies!"  Specifically, Santana combines a Mesa/Boogie Mark I head running through a Boogie cabinet with Altec 417-8H (or recently JBL E120s) speakers, and a Dumble Overdrive Reverb and/or a Dumble Overdrive Special running through a Brown or Marshall 4x12 cabinet with Celestion G12M "Greenback" speakers, depending on the desired sound. Shure KSM-32 microphones are used to pick up the sound, going to the PA. Additionally, a Fender Cyber-Twin Amp is mostly used at home.  During his early career Santana used a GMT transistor amplifier stack and a silverface Fender Twin. The GMT 226A rig was used at the Woodstock concert as well as during recording Santana's debut album. During this era Santana had also begun to use the Fender Twin, which was also used on the debut and proceedingly at the recording sessions of Abraxas.
Question: What is Amplifiers?
Answer: Carlos Santana's distinctive guitar tone is produced by PRS Santana signature guitars plugged into multiple amplifiers.

Background: The Aztecs (), were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521, during the time in which a triple alliance of the Mexica, Texcoca and Tepaneca tribes established the Aztec empire. The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica from the 14th to the 16th centuries. Aztec culture is the culture of the people referred to as Aztecs, but since most ethnic groups of central Mexico in the postclassic period shared basic cultural traits, many of the traits that characterize Aztec culture cannot be said to be exclusive to the Aztecs. For the same reason, the notion of "Aztec civilization" is best understood as a particular horizon of a general Mesoamerican civilization.
Context: In the first 50 years after the founding of the Mexica dynasty, the Mexica were a tributary of Azcapotzalco, which had become a major regional power under the ruler Tezozomoc. The Mexica supplied the Tepaneca with warriors for their successful conquest campaigns in the region and received part of the tribute from the conquered city states. In this way, the prestige and economy of Tenochtitlan gradually grew.  In 1396, at Acamapichtli's death, his son Huitzilihhuitl (Nahuatl: "Hummingbird feather") became ruler; married to Tezozomoc's daughter, the relation with Azcapotzalco remained close. Chimalpopoca (Nahuatl: "She smokes like a shield"), son of Huitzilihhuitl, became ruler of Tenochtitlan in 1417. In 1418, Azcapotzalco initiated a war against the Acolhua of Texcoco and killed their ruler Ixtlilxochitl. Even though Ixtlilxochitl was married to Chimalpopoca's daughter, the Mexica ruler continued to support Tezozomoc. Tezozomoc died in 1426, and his sons began a struggle for rulership of Azcapotzalco. During this struggle for power, Chimalpopoca died, probably killed by Tezozomoc's son Maxtla who saw him as a competitor.  Itzcoatl, brother of Huitzilihhuitl and uncle of Chimalpopoca, was elected the next Mexica tlatoani. The Mexica were now in open war with Azcapotzalco and Itzcoatl petitioned for an alliance with Nezahualcoyotl, son of the slain Texcocan ruler Ixtlilxochitl against Maxtla. Itzcoatl also allied with Maxtla's brother Totoquihuaztli ruler of the Tepanec city of Tlacopan. The Triple Alliance of Tenochtitlan, Texcoco and Tlacopan besieged Azcapotzalco, and in 1428 they destroyed the city and sacrificed Maxtla. Through this victory Tenochtitlan became the dominant city state in the Valley of Mexico, and the alliance between the three cities provided the basis on which the Aztec Empire was built.  Itzcoatl proceeded by securing a power basis for Tenochtitlan, by conquering the city-states on the southern lake - including Colhuacan, Xochimilco, Cuitlahuac and Mizquic. These states had an economy based on highly productive chinampa agriculture, cultivating floating gardens in the shallow lake Xochimilco. Itzcoatl then undertook further conquests in the valley of Morelos, subjecting the city state of Cuauhnahuac (today Cuernavaca).
Question: who conqured the lakes
Answer:
Itzcoatl