China's economy expanded more than five percent in the second quarter, official data shows, buoyed by strong exports but analysts warn that more work is needed to address sluggish consumer demand. "The national economy withstood pressure and made steady improvement despite challenges," Sheng Laiyun, Deputy Director of Beijing's National Bureau of Statistics, told a news conference. IMAGES AND SOUNDBITES ++ COMPLETES WITH VIDI_66R97CQ ++