It was not until ... that ..., sau "that" nhớ bỏ (didn't) nhưng các trường hợp (couldn't/ weren't/ wasn't/ hadn't) sau that chỉ bỏ "not" mà thôi.
39. The boy didn't tell the truth until his father threatened to punish him.
-> It ..............................................................................................................
40. The patient's heart condition didn't improve until she received that new treatment.
-> It .................................................................................................................
41. He didn't stop working until he felt too tired.
-> It ..................................................................................................................
42. The police didn't make any accusations until they had some proof.
-> It ....................................................................................................................
was not until his father threatened to punish him that the boy told the truth.
was not until the patient received that new treatment that her heart condition improved.
was not until he felt too tired that he stopped working.
was not until they had some proof that the police made some accusations.
