20. Select the word or phrase that makes this sentence grammatically correct: ........... picking up groceries one of the things you are supposed to do?
Answer: A
Is picking up groceries one of the things you are supposed to do?
The phrase "is picking up groceries" correctly forms the subject-verb agreement needed for the sentence to be grammatically correct. The singular subject "one" requires the singular verb "is" to match.
A) is
This option is correct because "is" agrees in number with the singular subject "one." The structure of the sentence requires a singular verb to match the singular subject, making this the appropriate choice.
B) am
This option is incorrect as "am" is the first-person singular form of the verb "to be," which does not agree with the subject "one." The sentence is not addressed to the speaker, hence "am" cannot be used here.
C) is it
This option is incorrect because "is it" introduces a question rather than completing the statement. The sentence requires a simple verb form to maintain its declarative nature, making "is it" unsuitable.
D) are
This option is incorrect because "are" is a plural verb form that does not agree with the singular subject "one." Using "are" would create a grammatical mismatch in the sentence structure.
Conclusion
The correct answer "is" maintains the necessary subject-verb agreement with the singular noun "one," ensuring the sentence is grammatically correct. All other options fail to provide the correct agreement or alter the sentence structure inappropriately, confirming "is" as the only suitable choice.