Exercise 2: Supply the correct form ofthe words in the brackets.
1. It (be) _____ not until her mother came that she went to bed.
2. It was not until his father threatened to punish him that he (tell) _____ the truth.
3. It was not until he (feel) ______ too tired that he stopped working.
4. It was not until we (begin) _____ primary school that we studied English.
5. It was not until he passed the university exam that he (start) ______ using cell phone.