Analyze the following sentences according to vocabulary use.

1. Thunderstorm and lightning posed a significant threat to the safety of the performers on stage so they had to call off the show.
2. The doctor couldn’t tell the patient with any certainty what the outcome of the operation will be.
3. If a child knows that he can never get away with a bad behavior, then he is less likely to do it.
4. The exam was a piece of cake means it was very boring.
5. Tom is the most ill-mannered and disrespectful person I know. Actually, he’s always lying.

Select the alternative that indicates all the correct sentences.