第一句前后时态不对,因该把if改成since,后面改成5000 yuan
generate改成generated作定语修饰traiffs表示产生的关税
they provide us with advice is transported separately这句话有两个动词了,改成they advise us that the goods can be transported separately
Which means pleasesend three firewalls to Shenzhen,Beijing and Shenyang separately这句也不对,不太明白你具体想表达的意思,如果单纯该这句话的语法那应该是it means we should send three separated firewalls to Shenzhen,Beijing and Shenyang
亲,你的毛病太多,有什么其他的在问我大侠：怎么说这句话啊，“以上的建议供您参考，最好是与您当地的物流公司咨询。”the above ideas for your reference, it is best to contact your local logisticscompany for more details.可以吗？just refer tothe advice above ，it is better to cosultyour local logistics company for more details.这样就没问题了