Passengers shouldn’t throw away their tickets

Chuyển các câu sau đây sang bị động : a) Passengers shouldn’t throw away their tickets. b) Candidates may not use dictionaries. c) A machine could do this mụch more easily d) His family will see him off at the airport. d) He is a dangerous man . They ought to lock him up e) Miss Snow had typed ten letters before lunchtime yesterday. f) Mrs Green had taken Alice to the dentist before you saw her