Chuyển câu chủ động thành câu bị động

chuyển câu chủ động thành câu bị động
             (past simple tense)
1) she didn't introduce me to her mother
2) all students attended the meeting
3) an earthquake destroyed the town
4) he didn't type the letter last night
           (past progressive tense)
1) tom was writing 2 poems
2) cows were eating grass on the meadow
3) you were wearing your new hat when i met you yesterday
4) her was planting different kinds of flowers in the garden