<p>-Sentence ID, parentheses are the underlined part</p>
<p>(From) about A.D. 700 to 1600, sculptors (created) (nearly) 1,000 colossal rock statues on the (remote) and tiny Easter Island.</p>
<p>The valuable stringed (instruments in) this display, (all more than) 300 years old, were carefully crafted (by artisans famous) in their day but (long since) forgotten.</p>
<p>-Sentence Improvement, parentheses are the underlined part</p>
<p>Dr. Chien-Shiung Wu (has disproved) a widely accepted theory of physics when she showed that identical nuclear particles do not always act alike.
A) has disproved
B) having disproved
C) disproved
D) disproves
E) disproving</p>
<p>Also, can someone please explain ALL the circumstances when the past present and present perfect tenses are used? I am really confused about those tenses...</p>
<p><a href=“From”>QUOTE</a> about A.D. 700 to 1600, sculptors (created) (nearly) 1,000 colossal rock statues on the (remote) and tiny Easter Island.
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<p><a href=“E”>b</a> No error**</p>
<p>1) “From” is correct because it introduces a starting point in the past (A.D. 700).
2) “Created” is correct because the simple past focuses on the event itself. The past perfect “had created” does not. When you say “I have prepared,” we do not care about the act itself; we care about the fact that you are STILL prepared in the present, otherwise we would have said “I prepared.” Also, when you specify a time period (A.D. 700 to 1600) you cannot use the past perfect. The perfect tense is used to indicate unspecified times in the past. Go to the links above to read more.
3) “Nearly” is correct because it describes the adjective “1,000” in that the exact number of rock statues lies below 1,000.
4) “Remote” is correct because it is an adjective that describes “Easter Island.”</p>
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<p><a href=“E”>b</a> No error**</p>
<p>1) “Instruments in” is correct because it is completes an adjective + noun + prepositional phrase sequence (stringed + instruments + in this display).
2) “All more than” is correct because “all” is a pronoun that refers to the aforementioned “instruments” and “more than [300 years old]” describes the pronoun’s age.
3) “By artisans famous” is correct because the entire adjectival phrase “famous in their day” is put after the noun because it has a preposition in it. You wouldn’t say “famous in their day artisans” or “famous artisans in their day.”
4) “Long since” is correct because “since” is an ADVERB that means “before now” or “ago.” The adverb modifies the verb/participle “forgotten.” The phrase means “long ago forgotten” or “forgotten long ago.” They are still forgotten in the present, and the particular event of their being forgotten isn’t the focus of the sentence, so we use the present perfect. Examples of “since” used in this context are: “I have not studied since,” “you have grown since.”</p>
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<p>The answer is the simple past “disproved” because the time is specified as “when she showed…” It brings us back to a specific point in the past, so the simple past is warranted if you want to describe a simultaneous event. You cannot say “has disproved…when” because “when she showed that…” strictly talks about the past.</p>