Final answer:
Mrs. Lewis put heavy-duty masking tape over Jason's mouth to prevent him from revealing secrets.
Step-by-step explanation:
Mrs. Lewis put heavy-duty masking tape over Jason's mouth because he and John had been telling secrets that their father did not want anyone to know. Mrs. Lewis was trying to stop them from revealing those secrets. The yellow smooches on their clothes were stains from a type of paper that stained everything it touched.