1.Engraving is a process which the surface of metal is first covered with an acid and then inscribed with some sharp instrument. 2.For many years ago much of what was possible to know was derived from inspiration or divination and did not involve the rational process of reasoning in wide use today. 3.Ayn Rand, ______ novels deal with the nature of capitalism in a democracy, is often taught in introductory courses in economics.? of many whose? whose many of? whose of many? many of whose 4.The formation of a rainbow occurs a process in which light is diffused at varying rates by the surrounding atmosphere resulting in the reflection of different wavelengths of light. 5.Though difficult, it possible for an adult learner of a new language to master the subtleties of the grammar and syntax of the new language. 6.When a bird molts, ______ loses its feathers, it is actually preparing itself for the regeneration of the lost feathers.? so its? as if? as when it? so that 7.The scientific method is a system which a problem or challenge is identified and possible solutions are created and tested, with the final results evaluated to determine the best approach to the resulting theory. 8.The Smithsonian Institution in Washington D.C. is home to the largest collect of Native American artifacts in the United States most of which remain uncatalogued and hidden from public view. 9.Many modern critics of American literature have called Mark Twain, born Samuel Clemens, ______ .? as America’s greatest writer? was America’s greatest writer? America’s greatest writer? to have been America’s greatest writer 10.In the modern era, face-to-face communication is becoming near as uncommon as hand-written letters. 讲解： 1.A This is a hard one to explain because we need to understand several different things about English grammar insgroupsto be able to choose the right answer. In a nutshell, we need a preposition here between the with the head noun and the sentence the surface of metal is first covered with an acid and then inscribed with some sharp instrument. In other words, the sentence that comes from the adjective clause would look like this: The surface of metal is first covered with an acid and then inscribed with some sharp instrument in [this] process. 2.Correction: years Generally speaking, we have two choices here: for many years or many years ago In other words, we cannot use for and ago together. Want to know why? Sure you do! It’s simple!!