<p>The gong, believed to have originated in Western Asia, reached China in the sixth century, where it continues to be used for a wide range of purposes, (including as) a military signal, a rhythmic accompaniment for vocal performance, and a ritual instrument.</p>
<p>A. including as
B. which include
C. which includes
D. including
E. they include as</p>
<p>A is correct. So, is "as" always necessary when introducing a list of things based on something?</p>
<p>I think it stems from the phrase before it “where it continues to be used”. The gong is used AS something.</p>
<p>The gong is used AS a military signal. You woudln’t say the gon is used a military signal would you?</p>
<p>It IS idiomatic to say that the gong was used “as” something. It is NOT idiomatic to say that the gong was used “a” something.</p>
<p>“used as” is not an idiom. it is a simple verb and a simple preposition. it is only idiomatic, or commonly used, because it is grammatically correct</p>
<p>the reason such a large percentage of sample test-takers got this question wrong is that as soon as they saw “including…” they thought a bunch of nouns would follow as examples of the previous noun (“he ate a variety of food, including eggs, tomatoes, pineapples, lobster, cake, turkey with gravy, and an apple”)</p>
<p>“as” is a preposition. prepositions can modify not only nouns but verbs</p>
<p>purposes are not objects, so you know the list is a continuation of the verb “used” and not the noun “range” or “purposes.” it’s not that “as” introduces a list but that it is a versatile preposition</p>
<p>it modifying the verb makes no sense:</p>
<p>incorrect choices B and C imply that the “wide range” includes or the “purposes” include the list of things. then, the sentence would inherently say “…continues to be used for a military signal…” which is obviously wrong.</p>
<p>“where it continues to be used for…, including as…”</p>
<p>Alright I get it now. Thanks a lot everyone :)</p>