News At Seven-Thirty: police narrowed the focus of the investigation into the latest acid attack; 8 more H1N1 flu cases were confirmed in Hong Kong; demand for childcare services has soared; WHO announced the alert is raised to the highest level; Iran President election ends by today; American official says Pyongyang may be preparing to conduct nuclear test; U.S. authorities charged a man with murder; Wang Rong was appointed as Shenzhen’s acting mayor; nominations opened for Macau's chief executive election; 2 window cleaners were hurt this morning; parents of the boy died in the knife attack questioned government's judgment; exhibition "Children of China" is held in HK.