Which sentence contains a form error in the must-and-have-to obligation contrast?
Next season, crews will have to record the depth of every sample.
Staff must to store duplicate seeds in a separate cold chamber.✓Correct answer
Yesterday, the caretaker had to drain the ornamental fountain.
Each apprentice has to log the kiln temperature before departure.
Explanation
The seed-bank rule is erroneous because must is followed by to store rather than the bare form store. The other sentences correctly mark present, past or future obligation with forms available for those time frames.