1. All of the flowers now raised here have developed from those _______ in the forest.        A. once they grew                        B. they grew once        C. they once grew                        D. once grew    2. In the office I never seem to have time until after 5:30 pm, _____ many people have gone home.        A. that                                         B. which        C. whose time                              D. by which time    3. Is this the reason _______ at the meeting for his carelessness in his work?        A. he explained                             B. what he explained        C. how he explained                      D. why he explained    4. Luckily, we’d brought a road map without ______ we would have lost our way.        A. it                                            B. that        C. this                                         D. which    5. When he was working there he caught a serious illness from _____ efforts he still suffers.        A. which                                     B. that        C. whose                                     D. what    6. It’s said that he’s looking for a new job, one ______ he can get more money to support his family.        A. when                                       B. where        C. that                                          D. which