【第 2 段建议】: 1. "We purchased the first set of Raymond mill" 应改为 "We purchased the first set of Raymond mills"（单复数一致性问题）。 2. "SBM quality is really trustworthy" 应改为 "SBM's quality is really trustworthy"（缺少所有格形式）。 3. "SBM --- trustworthy!" 应改为 "SBM—trustworthy!"（破折号格式不统一）。 其他部分无错误。