viết lại câu 1)But for your help,I couldn't have passed the exam =Had 2)She did't groduate from university until 1980 =It was not

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1.  Had it not been for your help, I couldn't have passed the exam. 

2. It was not until 1980 that she graduated from university. ( Cấu trúc : It was not until….that + mệnh đề (mãi cho đến khi ….thì ) )