AUGUST 4 (Reuters) — Wall Street ended lower on Monday (August 3) as tumbling oil prices dragged energy shares to a three-year low and factory data from China raised concerns about the world’s second-biggest economy. Energy stocks were the biggest losers among the main S&P sectors. Exxon Mobil and Chevron, which reported poor results on Friday, led the losses. Oil prices fell on fresh evidence of growing oversupply and data highlighting slowing demand in China. […]