(show)（）the ID. card, the students were allowed to enter the exam-room one by one.
举一反三
- No students are allowed to enter the room without _________ (permit).
- Laura is one of the top students in Grade One.
- Students all know that no one is allowed (speak) ______ in the reading room.
- Laura is one of the top students in Grade One. A: of B: top
- The personnel manager makes it clear that for security reasons, no one is allowed to enter the building ______ presenting a photo ID card. A: (A) unless B: (B) without C: (C) because D: (D) if