Answers:
1) Martha and Jim are in the office. Correct. 2) She is telling him a joke. Correct. 3) Jim made a copy of the report for Lucy and I. Incorrect. Jim made a copy of the report for Lucy and me. 4) I have to go. Mark is calling for Lucy and me. Correct. 5) Our co-workers love Martha’s cookies. Correct. 6) Jim and me are planning a surprise for Sue’s birthday. Incorrect. Jim and I are planning a surprise for Sue’s birthday.