【单选题】Hardly (he had) entered (the office) when he realized (that he had) (forgotten his) wallet.
【单选题】No sooner ______ there than he fell ill.
【单选题】(Hardly he had) entered (the office) when he realized (that he) (had forgotten) his wallet.
【单选题】Hardly (he had) entered (the office) when he realized (that he had) (forgotten) his wallet.
【单选题】He left early on the ______ that he had a had toothache and had to see the dentist.
【单选题】(Hardly he had) entered (the office) when he realized (that he) (had forgotten) his wallet.