LA Times: Su Aimin spat on the ground, and admired the result. “You see, it’s white,” said the 33-year-old production manager at Taiyuan Iron & Steel, pointing to his saliva. “Before, it was black. I’m not kidding.” Although Beijing is still struggling to make the skies clear for the Olympics, a massive cleanup effort before the Summer Games has given people here a taste of fresh air. They want to keep it that way, but business groups are likely to lobby for an …