英文解釈について(><)///
下記英文解釈について教えていただきたいです。よろしくお願いします♪
(1-37)A slice of bread represents centuries of evolution, starting with a single wild variety of wheat, which humans adapted to their needs. Originating ((1)ing形から始まるのはなぜでしょうか？)wheat cultivation in the valley of the Tigris River, wheat cultivation spread along the lines of civilization.
As wheat cultivation spread, different climates and soils served to produce new varieties. Eventually this became a conscious process, with different strains of wheat being crossed ((2)beingは何でしょうか？) to create entirely new kinds, combining ((3)combiningの主語はどれでしょうか？)the desirable characteristics of the parent strains.
As a result of this process of diversification, there are now thousands of varieties of wheat being grown ((4)beingは何でしょうか？)around the world.
(1-38) Although the United States is blessed almost a billion hectares of land suited for agriculture, that ((5),thatと続く理由?は何でしょうか?) alone does not explain its tremendous capacity for production.
(1-39) Scientists have achieved a broad understanding of how ((6)前置詞+how名詞節で副詞になるのでしょうか?) the human body transforms the raw materials it ((7)itが来る理由は何でしょうか?) obtains from food into the 45 nutrients needed to fuel activity and build cells. Unabsorbed residues pass though the small intense into the large intense, where ((9), whereと続く理由は何でしょうか?) they are stored for variable periods before being eliminated from the body.
(2-1) Most weight-losing effort, regaining weight and returning to the weight they were before. ((10)Most weight-losing effortが主語でしょうか?)
(2-2) He had several reasons for not eating meat, one being, ((11)one-beingと続く理由は何でしょうか?) his fondness for animals.
(2-5) Until the late 19th century, the smallest recognized unit of matter was the atom, of which （(12)of whichがくる理由は何でしょうか?)92 basic types comprise the 92 elements, which compose all oridinary materials.
