【第 2 段建议】: 1. "&" 应该为 "&"。 2. "company’s" 应该为 "company's"。 3. "more than 60 manufacturers around us" 可以改为 "more than 60 manufacturers around us." 以便句子结束。 4. "particle (<=20mm)" 应该为 "particle (≤20mm)"。 5. 句子 "It’s also convenient for overhaul, timely service and" 要补全，不应以“and”结尾。 其它部分无错误。