Q: Extract the answer to the question from the following context. Question: What characteristic of emission wavelengths affects the formation of an exciton in fluorescence imaging? Context: The structure of QD-LEDs used for the electrical-excitation scheme is similar to basic design of OLEDs. A layer of quantum dots is sandwiched between layers of electron-transporting and hole-transporting materials. An applied electric field causes electrons and holes to move into the quantum dot layer and recombine forming an exciton that excites a QD. This scheme is commonly studied for quantum dot display. The tunability of emission wavelengths and narrow bandwidth is also beneficial as excitation sources for fluorescence imaging. Fluorescence near-field scanning optical microscopy (NSOM) utilizing an integrated QD-LED has been demonstrated.
A: tunability

Q: Extract the answer to the question from the following context. Question: In addition to DNA and physical features, what else can be used to lump dogs into general groupings? Context: While all dogs are genetically very similar, natural selection and selective breeding have reinforced certain characteristics in certain populations of dogs, giving rise to dog types and dog breeds. Dog types are broad categories based on function, genetics, or characteristics. Dog breeds are groups of animals that possess a set of inherited characteristics that distinguishes them from other animals within the same species. Modern dog breeds are non-scientific classifications of dogs kept by modern kennel clubs.
A: function

Q: Extract the answer to the question from the following context. Question: What type of region was Dalmatia? Context: The topic of language for writers from Dalmatia and Dubrovnik prior to the 19th century made a distinction only between speakers of Italian or Slavic, since those were the two main groups that inhabited Dalmatian city-states at that time. Whether someone spoke Croatian or Serbian was not an important distinction then, as the two languages were not distinguished by most speakers. This has been used as an argument to state that Croatian literature Croatian per se, but also includes Serbian and other languages that are part of Serbo-Croatian, These facts undermine the Croatian language proponents' argument that modern-day Croatian is based on a language called Old Croatian.
A: city-states

Q: Extract the answer to the question from the following context. Question: Which is bigger, leagues square or acres? Context: Due in large part to the persuasion of representative Servando Teresa de Mier, Mexico City was chosen because it was the center of the country's population and history, even though Queretaro was closer to the center geographically. The choice was official on November 18, 1824, and Congress delineated a surface area of two leagues square (8,800 acres) centered on the Zocalo. This area was then separated from the State of Mexico, forcing that state's government to move from the Palace of the Inquisition (now Museum of Mexican Medicine) in the city to Texcoco. This area did not include the population centers of the towns of Coyoacan, Xochimilco, Mexicaltzingo and Tlalpan, all of which remained as part of the State of Mexico.
A:
leagues square