我国古代的伟大工程蕴含着中华民族文化与精神的底蕴。隋朝时修筑的促进南北经济文化交流的重要工程是(   )

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                                                                                                                                            闽中秋思
                                                                                                                                      （唐）杜荀鹤
                                                                                                                      雨匀紫菊丛丛色，风弄红蕉叶叶声。
                                                                                                                      北畔是山南畔海，只堪图画不堪行。