A verb form question tests whether the blank needs a main verb, saying what a noun does or is, or a describing form. Read around the blank, then read to the period to find its noun and main verb. After if, a shortened condition can leave out a pronoun and a form of be. Ask who does what: an -ing form can describe the doer, while an -ed describing form can describe what it happens to.
Hints
- Hint 1
Read from “a result that” to the period. Find the verb outside the if phrase.
- Hint 2
Check whether words are left out of the condition: how could you write the if phrase with a subject and a verb?
- Hint 3
Ask who would repeat what in human trials. What would the researchers do with the result?
Step-by-step
Count the main verbs, then test the result’s role
Step 1Sort the forms and find their noun
Sort the forms by job: a main verb says what a noun does or is. Replicate can be a main verb, while replicating and having replicated can't be one alone. An -ed form can be a main verb or only describe a noun, so we'll test it. In a result that, if ______ in human trials, the blank refers to the result.
- Step 2
Find the result’s main verb
What verb already goes with the result? Set if ______ in human trials aside for a moment, and could revolutionize antiviral treatment tells us what the result could do. So the result already has its main verb. But if can start a part with its own noun and verb, so let's check that condition.
- Step 3
Restore the shortened condition
How can if ______ in human trials work without a new noun before the blank? A condition can leave out a pronoun and a form of be, so let's test it as if it is followed by a describing form. The verb means to repeat or reproduce, and human trials would repeat the finding from cultured cells. So the result is repeated, rather than doing the repeating itself.
- Step 4
Test the form for the result
Which form describes something being repeated? Add was before the -ed form: the result was replicated says something was done to the result. So replicated can describe what's done to the result. In if ______ in human trials, it gives if replicated, short for if it is replicated. Choice C.