Complete the sentence: Only after the laboratory spectrometer ______ calibrated did the research team begin measuring the chemical samples.
Answer and explanation
Correct answer: B. had been
- Step 1: Identify temporal sequence in past narrative: The spectrometer was calibrated prior to the commencement of measurements in the past ('did the team begin').
- Step 2: Select tense for past action completed prior to another past event: Past perfect passive ('had been calibrated').
- Step 3: Confirm agreement with initial restrictive phrase 'Only after...'.
Answer
had been.
Why not the others: 'has been' is present perfect; 'is' is simple present; 'will be' is future tense, all clashing with the past indicative 'did... begin'.
Practise more Grammar, Syntax and Sentence Structure.
Free questions with an explanation for every one, and full timed University of Jordan English Proficiency Test (JU-EPT) mock tests.
More Grammar, Syntax and Sentence Structure questions
- Complete the sentence: Seldom ______ such extraordinary architectural precision as that exhibited in the ancient sandstone facades of Petra.
- Complete the sentence: The higher education accreditation committee required that the university dean ______ all relevant faculty research p…
- Choose the correct transition: The excavation in Gadara faced severe winter rainfall; ______, the archaeologists uncovered two pristine Roma…
- Complete the sentence: Had the hydrological engineers ______ the flash flood warning system earlier, the valley settlements would have avoid…
- Select the correct pronoun: Neither the department head nor the research associates ______ willing to compromise on the experimental protoco…
- Complete the sentence: The university administration has decided ______ the deadline for graduate scholarship applications.