Find the incorrect sentences. a We mustn't be late for the lecture. b You must lose some weight.
c Caroline doesn't have to work on Saturdays. d You mustn't go now but you can if you want to. e Mark hasn't to worry about the exam--he's done lots of work. f You don't have to stay out later than ten. That's when they lock the door. g You needn't drink water from the river: it's dirty. h Relax! We mustn't leave till ten o'clock. i You have to leave your bags at the desk. j You'll must find a job very soon.