17. The primary purpose of the passage is to
(A) discuss the validity of a hypothesis
(B) summarize a system of general principles
(C) propose guidelines for future argument
(D) stipulate conditions for acceptance of an interpretation
(E) deny accusations about an apparent contradiction
18. It can be inferred from the passage that the author believes which of the following about Malory's works?
I. There are meaningful links between and among the romances.
II. The subtleties of the romances are obscured when they are taken as one work.
III. Any contradictions in chronology among the romances are less important than their over- all unity.
(A) I only (B) III only
(C) I and III only (D) II and III only
(E) I, II, and III
19. The author of the passage concedes which of the following about the Vinaver theory?
(A) It gives a clearer understanding of the unity of Malory's romances.
(B) It demonstrates the irrationality of considering Malory's romances to be unified.
(C) It establishes acceptable links between Malory's romances and modern novels.
(D) It unifies earlier and later theories concerning the chronology of Malory's romances.
(E) It makes valid and subtle comments about Malory's romances.
20. It can be inferred from the passage that, in evaluating the Vinaver theory, some critics were
(A) frequently misled by the inconsistencies in Malory's work
(B) initially biased by previous interpretations of Malory's work
(C) conceptually displeased by the general interpretation that Vinaver rejected
(D) generally in agreement with Vinaver's comparisons between Malory and modern novelists
(E) originally skeptical about Vinaver's early conclusions with respect to modern novels
We can distinguish three different realms of matter, three levels on the quantum ladder. The first is the atomic realm, which includes the world of atoms, their interactions, and the structures that are formed by them, such as molecules, liquids and solids, and gases and plas- mas. This realm includes all the phenomena of atomic physics, chemistry, and, in a certain sense, biology. The energy exchanges taking place in this realm are of a rela- tively low order. If these exchanges are below one elec- tron volt, such as in the collisions between molecules of the air in a room, then atoms and molecules can be regarded as elementary particles. That is, they have "conditional elementarity" because they keep their iden- tity and do not change in any collisions or in other pro- cesses at these low energy exchanges. If one goes to higher energy exchanges, say 104 electron volts, then atoms and molecules will decompose into nuclei and electrons; at this level, the latter particles must be consi- dered as elementary. We find examples of structures and processes of this first rung of the quantum ladder on Earth, on planets, and on the surfaces of stars.
The next rung is the nuclear realm. Here the energy exchanges are much higher, on the order of millions of electron volts. As long as we are dealing with phenom- ena in the atomic realm, such amounts of energy are unavailable, and most nuclei are inert: they do not change. However, if one applies energies of millions of electron volts, nuclear reactions, fission and fusion, and the processes of radioactivity occur; our elementary par- ticles then are protons, neutrons, and electrons. In addi- tion, nuclear processes produce neutrinos, particles that have no detectable mass or charge. In the universe, ener- gies at this level are available in the centers of stars and in star explosions. Indeed, the energy radiated by the stars is produced by nuclear reactions. The natural radioactivity we find on Earth is the long-lived remnant of the time when now-earthly matter was expelled into space by a major stellar explosion.
The third rung of the quantum ladder is the subnu- clear realm. Here we are dealing with energy exchangers of many billions of electron volts. We encounter excited nucleons, new types of particles such as mesons, heavy electrons, quarks, and gluons, and also antimatter in large quantities. The gluons are the quanta, or smallest units, of the force (the strong force) that keeps the quarks together. As long as we are dealing with the atomic or nuclear realm, these new types of particles do not occur and the nucleons remain inert. But at subnu- clear energy levels, the nucleons and mesons appear to
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