【第 2 段建议】: 1. "He has river resources." 应为 "He had river resources." 2. "The excellent crushers, especially the cone crusher, ca" 应为 "The excellent crushers, especially the cone crusher, can." 3. "7 hour;" 应为 "7 hours;" 4. "It's first time" 应为 "It's the first time" 5. "machine-made sand" 前应加 "invest in" 变为 "invest in machine-made sand." 6. "He finally decided to invest river resources" 建议改为 "He finally decided to invest in river resources." 其他问题的统计、语法和标点没有发现明显错误。