After four races and flying across half a dozen different time zones in the last week, Kikkan Randall probably had a tough time telling up from down and left from right on Wednesday. But in the U.S. 30 k National Championship, she could still do the one thing she does best: ski fast, and win. “My body really doesn’t know what to think,” she said. “But it’s in good shape, so we’ll just keep rolling.”...