题目内容：
阅读材料，回答题。The Adjustment in Understanding of Man's Relation to the Physical Universe
Nowadays the scattering of galaxies and the astounding abundance of stars are forcing those who ponder such matters to a further adjustment of their concept of the place and function of man in the material universe.
In the history of the51human mind, with its increasing knowledge of the surrounding context, there must have been a time when the philosophers of the52tribes began to realize that the world was not simply centered on man himself. The geocentric concept, which accepted a universe centered on the earth, then became common53
The second adjustment in the understanding of man's relation to the physical universe was not generally acceptable54the sixteenth century. Copernican revolution soundly55the heliocentric Concept, the theory of a universe56on the sun. Man is a stubborn adherent to official dogma; eventually, however, he accepted the sun as the center.
Then, forty years ago, came the need for a third adjustment. This57has deeply exploded man's pride and58, for it has carried with it the knowledge of the appalling number of galaxies.
The galactocentric universe59puts the earth and its life near the edge of one great galaxy in a universe of millions of galaxies. Man becomes peripheral among the billions of stars of his own Milky Way; and, according to the revelations of paleontology and geochemistry, he is60and apparently transient in the61of cosmic time.
The downgrading of the earth and sun and the elevation of the galaxies is not the end of this62of scientific pilgrims through philosophic fields. The need for another63adjustment now64not wholly unexpected by scientists,65wholly the result of one or two scientific revelations.
Our new problem concerns the spread of life throughout the universe. As unsolicited spokesmen for all the earthly organisms of land, sea, and air, we ask the thrilling question: Are we alone?
请在第__(51)__处填上正确答案。 A．ingenious
B．evolving
C．creative
D．eligible
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