A verb question about an imagined past tests both time and who does what. Find the subject and ask whether it does something or has something done to it. Active verbs say what the subject does; passive verbs use be plus a form like called or written to say what happens to it. Then follow the time clues: a past condition that didn't happen uses had, and its imagined result uses would have. Every verb form needs a clue in the sentence.
Hints
- Hint 1
Start by finding the subject of the blank. Who does the recording, and what gets recorded?
- Hint 2
Look for the time of the replication. Which part of the sentence sets up a possibility, and which part reports what happened?
- Hint 3
Try rewriting the opening with if. How should the words after the comma relate to that imagined condition?
Step-by-step
Follow the subject and the past condition
Step 1Find who does the recording
Each choice agrees with the same numerical values, the subject at the blank. Who does the recording? The phrase by independently calibrated equipment names the recorder, so the values are recorded by the equipment, which calls for a passive verb. Would not have recorded is active: it would make the values record something, rather than be recorded.
- Step 2
Separate the imagined result from what happened
Had the elevated radium readings reflected only a calibration error can be rewritten as if the readings had reflected only a calibration error. Is that what happened, or a possibility we're asked to imagine? The ending, instead, that equipment recorded those values, reports what happened: the independent equipment got the same readings. The blank gives an imagined past result: if only the original instrument had been at fault, separate equipment wouldn't have repeated its values.
- Step 3
Choose the form for the imagined result
The words during the 1932 replication put the result in the past. Which form marks an imagined result in that past? A past condition that didn't happen pairs with would have in its result. Will not have been recorded looks ahead to the future, while had not been recorded describes something that hadn't happened before another time in the past, rather than giving the condition's imagined result.
- Step 4
Build the passive verb
How do we make that result passive for the same numerical values? Put been between have and recorded, because a passive verb needs a form of be with recorded. The complete form is would not have been recorded. Choice B.