【第 2 段建议】: 1. "It's first time" should be "It's the first time". 2. "aggregate industry" should be "the aggregate industry". 3. "he decided to produce aggregate by himself" should be "he decided to produce aggregates by himself" for consistency with plural usage. 4. "Main equipment: PE500*750 jaw crusher (1 set), HPC220 cone crusher (1 set), VSI9526 sand making machine (1 set), etc." should end with "etc." not a period. 5. "we used to choose other companies' equipment" could be better phrased as "we used to choose equipment from other companies". 6. "timely once our production line was confronted with small troubles" should be "timely whenever our production line was confronted with small troubles".