News At Seven-Thirty highlights: Hospital denied wrongdoing for negligence; Temperature drop as cold front approach; Cold weather wreaking havoc across border; Beijing boost economic cooperation with Taiwan; Fresh clashes erupted in Greece; Jet veered off runway and caught fire in US; 30,000 US troops to be sent to Afghanistan; Violence flared in Gaza; Moscow market explosion unjured nine; Negative impact of Christmas lighting; Runners preparing for annual Marathon; French yachtsman rescued by Australian Navy.