Put the verbs in brackets into the past perfect or the past perfect continuous . 13 .Mrs Edwards (make biscuits by the time her children came home. 14. Joh (try) to fix his computer for two hours before he decided to call a professional.
17.Liza was exhausted yesterday. She (study) for a history exam all day

13 .Mrs Edwards had made biscuits by the time her children came home. 14. Joh had been trying to fix his computer for two hours before he decided to call a professional. 17.Liza was exhausted yesterday. She had been studying for a history exam all day