NOVELTY - Changing (M1) a molecular structure of a biomass feedstock, involves preparing the biomass feedstock by reducing at least one dimension of individual piece of biomass; pretreating the biomass feedstock using at least two different pretreatment methods that each change the molecular structure, where the different pretreatment methods are selected from radiation, sonication, pyrolysis, and oxidation; and processing the prepared and pretreated biomass feedstock to produce a product.    USE - For changing molecular structure of a biomass feedstock useful for making product including combustible fuel containing hydrogen, alcohol and hydrocarbons; for making fiber-resin composite; and for making irradiated wood product. The alcohols are ethanol, n-propanol, isoproanol or n-butanol. The biomass feedstock is paper, paper products, paper waste, wood, particle board, sawdust, agricultural waste, sewage, silage, grasses, rice hulls, bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca, straw, corn cobs, corn stover, switchgrass, alfalfa, hay, rice hulls, coconut hair, cotton, synthetic celluloses, seaweed or algae (claimed). The carboxylic acids are e.g. formic acid, acetic acid, propionic acid, and butyric acid. The hydrocarbons are methane, ethane, propane, pentane, and n-hexane. The other products and co-products that are produced are human food, animal feed, and pharmaceutical.    ADVANTAGE - The process provides cellulosic and/or lignocellulosic materials that have a lower molecular weight and/or crystallinity relative to a native material. The process provides materials that are more readily utilized by a variety of microorganisms to produce useful products; and provides materials that are more readily utilized by a variety of microorganisms because of their lower molecular weight, lower crystallinity, and/or enhanced solubility. The process provides synergies and reduces overall energy input required in comparison to any single process.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) making (M2) a product such as a combustible fuel, involving: providing a material comprising a carbohydrate produced by a process involving pretreating the biomass feedstock with at least two of radiation, sonication, pyrolysis, and oxidation; and contacting the material with a microorganism having the ability to convert at least a portion, e.g. at least about 1 wt.% of the material to the product, such as the combustible fuel;    (2) a biomass feedstock processing system (S1) comprising: a biomass feedstock preparation module for reducing size of pieces of biomass, at least two of the pretreatment modules: a radiation module arranged to apply radiation to the biomass, a sonication module arranged to apply sonic energy to the biomass, an oxidation module arranged to oxidize the biomass, and a pyrolysis module arranged to apply heat to the biomass; and a biomass transportation subsystem to move the biomass to and between modules within the processing system, where the at least two pretreatment modules are arranged in series and/or are arranged to treat a portion of the biomass at about the same time;    (3) a system (S2) comprising a reaction vessel containing the pretreated biomass material comprising the carbohydrate, where the pretreated biomass material is produced by the methods (M1) and (M2);    (4) a carbohydrate material produced by a process involving pretreating a sheared biomass feedstock with at least one of radiation, sonication, oxidation, pyrolysis and steam explosion;    (5) a composition comprising a cellulosic or a lignocellulosic material having a peak maximum molecular weight of less than about 25000, and a crystallinity of less than about 55%;    (6) making a composite such as a fiber-resin composite, involving irradiating a fibrous material comprising a first cellulosic and/or lignocellulosic material having a first molecular weight to provide a second cellulosic and/or lignocellulosic material having a second molecular weight higher than the first molecular weight; combining the second cellulosic and/or lignocellulosic material with a material, such as a resin to provide the composite; and optionally irradiating the composite; or combining a material such as a resin, with the fibrous material comprising the cellulosic and/or lignocellulosic material having the first molecular weight to provide a composite comprising the fibrous material and a matrix; and irradiating the composite to increase molecular weight of the first cellulosic and/or lignocellulosic material within the matrix such as a resin matrix; and    (7) making (M3) an irradiated wood product involving providing a wood product comprising a first carbohydrate-containing material having a first molecular weight; and irradiating the wood product to provide an irradiated wood product comprising a second carbohydrate-containing material having a second molecular weight higher than the first molecular weight.