用正确的时态完成句子
【小题1】Thomas _______________________（一直患重感冒）before he took the final exam.
【小题2】He said that he _______________________（一直在做化学实验）and had not finished it yet.
【小题3】Allen _______________________（复习功课）all the night. No wonder he was so tired.
【小题4】Helen _______________________（把钥匙忘在了办公室里）so she had to wait until her husband came home.
【小题5】The two countries _______________________（一直在争夺石油）before they reached a peace agreement.