Which sentence contains an error in the participle used after a modal passive?
Every alarm should be tested before the building opens.
The sealed case can be carried by two people.
The workshop screen must be repair before use.✓پاسخ درست
Unused badges may be collected at the front desk.
توضیح
The workshop sentence is erroneous because be repair uses a base form after the passive auxiliary. A modal passive needs a past participle there, as the other sentences demonstrate with tested, carried, and collected.