Fill each gap with the most appropriate option from the list provided.
Four weeks _____ enough for the police to conclude their investigation?
Answer Details
The correct option to fill the gap is "is". This is because the subject of the sentence is "four weeks", which is a singular noun and requires a singular verb to agree with it. "Is" is the singular form of the verb "to be", so it is the correct choice here. The sentence means that the speaker believes that a period of four weeks is sufficient for the police to complete their investigation.