Several fields of discrete mathematics, particularly theoretical computer science, graph theory, and combinatorics, are important in addressing the challenging bioinformatics problems associated with understanding the tree of life.

Several institutions, besides those already mentioned, played important parts.

Several billion kilograms of polyesters are produced industrially annually, important products being polyethylene terephthalate, acrylate esters, and cellulose acetate.

Several important cinematic movements, including the Nouvelle Vague, began in the country.

Several types are existent in Qing dynasty and used in dishes of stewing hams ( 火腿炖肘子 ), and vegetables, or for a wide variety of soup and important soup stocks.

Several important institutional changes took place in this period, such as free and mandatory schooling introduced 1842 ( as first country in the world ), the abolishment of a previous national monopoly on trade in handicrafts in 1846, and a stock company law in 1848.

His critically acclaimed book Lyrics on Several Occasions of 1959, an amalgam of autobiography and annotated anthology, is an important source for studying the art of the lyricist in the golden age of American popular song.

Several formerly important franchise courts were not officially abolished until Courts Act of 1971.

Several important buildings and structures were built during this time, including the Kansas City City Hall and the Jackson County Courthouse — both added new skyscrapers to the city's growing skyline.

Several industry groups also recognize light pollution as an important issue.

Several types of molecules are particularly important during morphogenesis.

Several of the more important ways observations can be affected by human psychology are given below.

Several other important engravers also made cards, including Master ES and Martin Schongauer.

Several economically important products come from Rosaceae, including many edible fruits ( such as apples, apricots, plums, cherries, peaches, pears, raspberries, and strawberries ), almonds, and ornamental trees and shrubs ( such as roses, meadowsweets, photinias, firethorns, rowans, and hawthorns ).

Several important political innovations of classical antiquity came from the Greek city-states and the Roman Republic.

Several Referendums supported the state being in control of the most important utilities and energy companies.

Several important modern cities, including Stockholm and Lviv, were founded in the 1250s.

Several important cultural achievements were made in the decade, including publication of Roger Bacon's important scientific work Opus Majus and Thomas Aquinas ' Summa contra Gentiles.

Several lakesthe most important of which are Lake Herăstrău, Lake Floreasca, Lake Tei, and Lake Colentinastretch across the northern parts of the city, along the Colentina River, a tributary of the Dâmbovița.

Several singular oak trees, such as the Royal Oak in Britain and the Charter Oak in the United States, are of great historical or cultural importance ; for a list of important oaks, see Individual oak trees.

Several important trade routes from India and China ( including the Silk Road ) passed through Bactria and, as early as the Bronze Age, this had allowed the accumulation of vast amounts of wealth by the mostly nomadic population.

Several of Gauthier's students are now important moral, political, and legal philosophers in the United States and Canada.

Several important features of visual perception can be traced to the retinal encoding and processing of light.

Several important diseases of the nervous system are associated with dysfunctions of the dopamine system.

Several in-depth studies of salamander genera in fossil beds in Montana show that six of seven genera were unchanged after the event.

Several fossil birds have been erroneously ascribed to the kingfishers, including Halcyornis, from the Lower Eocene rocks in Kent, which has also been considered a gull, but is now thought to have been a member of an extinct family.

Several of these fossil forms are ichnotaxa ( that is, classified according to the organism's footprints or other trace rather than its body ) and their association with those described from distinctive bones is contentious and in need of revision pending more good material.

Several important archaeological and palaeontological sites, some of which have yielded fossil hominoids and hominins, are present in the Miocene to Pleistocene sedimentary sequences of the Tugen Hills.

Several objects made of bone and flint stone and also two human molars and incisors belonging to fossil Homo erectus have been found in Fontana Ranuccio.

Several fossil species have been described, but their distinctness is not firmly established in all cases:

Several waste gasification processes have been proposed, but few have yet been built and tested, and only a handful have been implemented as plants processing real waste, and most of the time in combination with fossil fuels.

Several fossil species have been identified, including one from Africa.

Several fossil species are known, and show adaptations to a wide range of different diets, from strict herbivory to possible carrion-eating ( in Tetraconodon ).

Several fossil species of Branta have been described.

Several mammalian fossils were collected along with a left lower canine, originally identified as a non-human primate, later revealed as the site's first fossil hominin in 1979 by P. Andrews and T. White.

Several fossil animals have been interpreted as having prehensile tails, including several Late Triassic drepanosaurs, and possibly the Late Permian synapsid Suminia.

Several fossil species, such as Comptonia colombiana have been described, showing that the genus once had a much wider distribution throughout the Northern Hemisphere.

Several other genera and various fragmentary fossil remains are also known.

Several various mammal species inhabit the land ( red deer, roe deer, wild boar, wild cat, pine marten, stone marten, weasel, sable, otter, etc .).

Several mammal species originated in the Palearctic, and spread to the Nearctic during the ice ages, including the Brown Bear ( Ursus arctos, known in North America as the Grizzly ), Red Deer ( Cervus elaphus ) in Europe and the closely related Elk ( Cervus canadensis ) in far eastern Siberia, American Bison ( Bison bison ), and Reindeer ( Rangifer tarandus, known in North America as the Caribou ).

Several other extinct groups of Mesozoic animals that are traditionally considered to be mammals ( such as Morganucodonta and Docodonta ) are now placed just outside Mammalia by those who advocate a ' crown-group ' definition of the word " mammal ".