Hereinafter please other questions of this article.21. the primary topic of the passage is which of the following?(A) The interaction of the realms on the quantum ladder
(B) Atomic structures found on Earth, on other planets, and on the surfaces of stars
(C) Levels of energy that are released in nuclear reactions on Earth and in stars
(D) Particles and processes found in the atomic, nuclear, and subnuclear realms
(E) New types of particles occurring in the atomic realm
22. According to the passage, radioactivity that occurs naturally on Earth is the result of(A) the production of particles that have no detectable mass or electric charge
(B) high energy exchanges on the nuclear level that occurred in an ancient explosion in a star
(C) processes that occur in the center of the Sun, which emits radiation to the Earth
(D) phenomena in the atomic realm that cause atoms and molecules to decompose into nuclei and electrons
(E) high-voltage discharges of electricity that took place in the atmosphere of the Earth shortly after the Earth was formed
23. The author organizes the passage by(A) making distinctions between two groups of par- ticles, those that are elementary and those that are composite
(B) explaining three methods of transferring energy to atoms and to the smaller particles that constitute atoms
(C) describing several levels of processes, increasing in energy, and corresponding sets of particles, generally decreasing in size
(D) putting forth an argument concerning energy levels and then conceding that several qualifi- cations of that argument are necessary
(E) making several successive refinements of a defi- nition of elementarity on the basis of several groups of experimental results
24: According to the passage, which of the following can be found in the atomic realm?(A) More than one level of energy exchange
(B) Exactly one elementary particle
(C) Exactly three kinds of atomic structures
(D) Three levels on the quantum ladder
(E) No particles smaller than atoms
25. According to the author, gluons are not(A) considered to be detectable
(B) produced in nuclear reactions
(C) encountered in subnuclear energy exchanges
(D) related to the strong force
(E) found to be conditionally elementary
26. At a higher energy level than the subnuclear level described, if such a higher level exists, it can be expected on the basis of the information in the pas- sage that there would probably be(A) excited nucleons (B) elementary mesons
(C) a kind of particle without detectable mass or charge
(D) exchanges of energy on the order of millions of electron volts
(E) another set of elementary particles
27. The passage speaks of particles as having conditional elementarity if they(A) remain unchanged at given level of energy exchange
(B) cannot be decomposed into smaller constituents
(C) are mathematically simpler than some other set of particles
(D) release energy at a low level in collisions
(E) belong to the nuclear level on the quantum ladder