Anyone good at riddles can help me

Which of these sentences has an error in subject-verb agreement? a. official procedures calls for students who are tardy three times to serve detention. b. as a result of her efforts, a team of volunteers signs up every month to clean the city's parks. c. the committee of parents protested loudly at the school board meeting. d. each of the neighbors brings a dish to share at the pot-luck gathering.

Whom does macbeth have murdered to keep one if the witches prophecies from coming true a. malcolm and donalbain b. king duncan c. the thane of cawdor d. banque and his son

What happens once in a minute twice in a moment and never in a thousand years?