31. Mrs Brown's children are used to be picked up after school every day

be=> being

32. Jack got into trouble when he refused opening his briefcase for the customs officer

opening=> to open

33. We regret informing you that your application has been turned down

informing => to inform

34. Tell me about your school days. Do you remember to go to school for the first time?

to go => going

35. Tom had just had his hair cut. We couldn't help laughing when see him

had just had => just had had