2015年MBA阅读理解强化练习题20

　　By synthesizing electrides from a variety of materials, one can vary the geometry of the anionic cavities and their relation to the surrounding cations. The resulting properties may make it possible for electrides to become a basis for economically useful new materials and devices. For instance, because the electrons in some electrides are very weakly bound, these crystals could be effective as photosensitive detectors, in which an impinging photon liberates an electron, resulting in a small electric current. The same weak binding could also make electrides useful in solar energy converters and as cathodes in batteries. One obstacle is the tendency of electrides to decompose through reaction with air and water. Researchers are seeking ways to increase their stability.

　　1. The text is primarily concerned with discussing

　　[A] a way to isolate electrons.

　　[B] the characteristics of a new kind of crystal.

　　[C] the structure of an ionic salt.

　　[D] commercial uses for electrides.

　　2. In the first paragraph, the author is primarily concerned with

　　[A] introducing a variant on the standard atomic theory.

　　[B] describing how chlorine atoms can become negatively charged.

　　[C] describing some early research at Michigan State University.

　　[D] providing background for the technical discussion to follow.

　　3. According to the text, the defining characteristic of an electride is which of the following?

　　[A] Its positive are of particularly low mass.

　　[B] Its ions possess identical electrical charges.

　　[C] It contains a framework of regularly stacked ions.

　　[D] Its negative ions consist solely of electrons.

　　4. It can be inferred from the text that anions behaving as “simple charged spheres” (line 2, paragraph 3) could be expected to

　　[A] readily lose electrons and become positively charged.

　　[B] move freely in and out of their cavities.

　　[C] respond to photons by liberating electrons.

　　[D] remain fixed relative to their cations.

　　5. With which of the following statements regarding electrides would the author most likely agree?

　　[A] They have proven themselves to be of great commercial value.

　　[B] Their future commercial value is promising but uncertain.

　　[C] They are interesting but of no practical value.

　　[D] They have commercial value mainly in solar energy applications.