An agreement question tests whether a verb matches its true subject, even when other nouns get in the way. Sort the verb forms by number, then find the true subject by crossing out descriptions and extra information. One thing takes a singular verb, usually ending in -s; more than one takes a plural verb. If punctuation changes too, check the marks around the extra information. Extra information in the middle needs the same mark at both ends.
Hints
- Hint 1
Read from indicates that and check whether the words after it have their own subject and verb.
- Hint 2
Focus on the description beginning with binding. If you set that description aside, which noun is left for the blank's verb?
- Hint 3
Test that noun with it or they, then check where any extra information between it and the verb starts and ends.
Step-by-step
Find the subject and close the insert
Step 1Sort the verb forms
Sort the verb forms: derive is plural, and the forms ending in -s are singular. What about deriving? It needs a helper such as is to work as a main verb, the verb that completes what a subject does or is. After indicates that, look for a subject and its own verb, because indicates belongs to the analysis.
- Step 2
Find what needs the verb
What is said to come from a plant resin? In the adhesive binding a strip of silver leaf, binding starts a description of the adhesive that continues to the central panel. That description doesn't make the strip or the panel the subject. The comparison beginning with unlike has the verb sampled, but that verb says what conservators did to the coatings. The adhesive is one thing, and it still needs its own verb to say where it comes from.
- Step 3
Close the extra information
Can we remove the words beginning with unlike the coatings? They're an insert, extra information the sentence can do without, because the adhesive still comes from a plant resin when that comparison is gone. The comma after panel opens the insert, so a second comma must close it right before the adhesive's own verb.
- Step 4
Match the verb and the punctuation
Now replace the adhesive with it: it derives from a plant resin. The wording panels, derives gives us a singular main verb after the closing comma, so the adhesive's part of the sentence is complete. Choice C.