愛知医科大学英語2012年第3問
What would happen if we were to start thinking about food as less of a thing and more of a relationship? In nature, that is of course precisely what eating has always been; relationships among species in systems we $\fbox{16}$[(1)call (2)refer (3)regard] food chains, or food webs, that reach all the way down to the soil. Species coevolve with the other species $\fbox{17}$[(1)that (2)what (3)how] they eat, and very often there develops a relationship of interdependence: I’ll feed you if you spread around my genes. A gradual process of mutual adaptation transforms something like an apple or a squash $\fbox{18}$[(1)for (2)into (3)of (4)with] a nutritious and tasty food for an animal. Over time and through trial and error, the plant becomes tastier (and often more conspicuous) in order to gratify the animal's needs and desires, while the animal gradually $\fbox{19}$[(1)deserts (2)relies (3)acquires] whatever digestive tools(enzymes, for example)it needs to make optimal use of the plant.
Similarly, the milk of cows did not start out as a nutritious food for humans; in $\fbox{20}$[(1)between (2)fact (3)case] , it made them sick until people who lived around cows evolved the ability to digest milk as adults. The gene for the production of a milk-digesting enzyme called lactase used to $\fbox{21}$[(1)switch (2)switching (3)being switched] off in humans shortly after weaning until about five thousand years ago, when a mutation that kept the gene switched on appeared and quickly spread through a population of animal herders in north-central Europe. Why? Because the people $\fbox{22}$[(1)possessing (2)possessing by (3)possessed (4)possessed with] the new mutation then had access to a terrifically nutritious new food source and as a consequence were able to produce more offspring than the people who lacked lt. This development proved much to the $\fbox{23}$[(1)adventure (2)advantage (3)advertisement] of both the milk drinkers and the cows, whose numbers and habitat (and health) greatly improved as a result of this new symbiotic relationship.
Health is, among other things, the product of being in these sorts of relationships in a food chain-a great many such relationships in the case of an omnivorous creature like man. It $\fbox{24}$[(1)assumes (2)considers (3)follows] that when the health of one part of the food chain is disturbed, it can affect all the other creatures in it. If the soil is sick or in some way deficient, so will be the grasses that grow in that soil and the $\fbox{25}$[(1)vegetarians (2)bacteria (3)cattle] that eat the grasses and the people who drink the milk from them.
注）wean：gradually stop feeding a baby with its mother’s milk (出典 Michael Pollan. In Defense of Food An Eater's Manifesto. New York: Penguin Books;2009)