【明報專訊】YESTERDAY (July 1) Hong Kong celebrated the 18th anniversary of its return to Chinese sovereignty. Citizens chose to mark the anniversary by engaging in different activities as they had done over the years. This year, however, as the government's constitutional reform proposal was defeated not long ago in the Legislative Council, society is deeply embroiled in internal arguments, confrontations and rifts, and the overall atmosphere is gloomier than in the previous years. In fact, in the wake of the fight over constitutional reform over the past two years, how "one country, two systems" should be pursued in future is a question the central government, the SAR government and the Hong Kong people have to consider.