By Martin Quin Pollard WUZHOU, China (Reuters) -Chinese investigators began examining the cockpit voice recorder from a China Eastern Airlines jet that plunged into mountainside with 132 people on board as recovery crews searched muddy fields on Thursday for a second black box. The recording material from the first black box, found on Wednesday, appeared to have survived the impact of Monday’s crash in relatively good shape, a Civil Aviation Administration of China (CAAC) official said. The cockpit voice recorder would provide investigators with details of communications between the flight’s t…