Select the correct verb form:

A) Then 50 cc of Lidocaine was instilled.
B) Then 50 cc of Lidocaine were instilled.
My answer is A, were doesn't seem to fit.

Could you also look at this one for me?

Select the correct verb form:
A) Mumps are a common childhood disease.
B) Mumps is a common childhood disease.
I answered B

I disagree with your first answer.

The second one is right.

Thank you:)

You're welcome.

Just took a test and the answer A on the first question is right. Is not were. It is was. I choose were and got it wrong. Was is correct.

You are correct! The correct verb form in this sentence is A) "was instilled." In this sentence, "50 cc of Lidocaine" is a singular noun phrase, so it should take a singular verb form. The word "was" is the past tense form of the verb "to be," which agrees with the singular noun phrase. On the other hand, "were" is the past tense form of the verb "to be," but it is used for plural noun phrases. Therefore, your intuition is correct, and option A is the correct verb form in this sentence.