【明報專訊】SHENZHEN'S mayor Chen Rugui announced the other day that the gross domestic product of the city had reached 2.2 trillion yuan in 2017. This means Shenzhen has risen to become the third biggest city nationwide just behind Beijing and Shanghai. The day of the announcement coincided with the 26th anniversary of the beginning of Deng Xiaoping's Southern Tour during which he made a series of landmark speeches. Now that Shenzhen has surpassed Deng's expectations in various aspects, foreseeably it will rely further on high technology as the motive force when it seeks to move to the next stage. How Hong Kong can make its own breakthrough in this regard is a topic worth pondering on.