The United States clocked a world record 3 minutes 37.43 seconds to take Olympic gold in the mixed 4x100m medley relay at Paris Games. It was an improvement of 0.15s from the previous world record, which belonged to Britain. The Chinese team took silver while Australia claimed bronze. This is only the second world record set at the Paris Games. The other came from China’s Pan Zhanle in the men’s 100m freestyle. Athletes, experts and coaches have been debating why has it been so hard to see world records in France. One theory for the slower-than-expected times appears to be a pool that is sligh…