Unit4的答案如下：第一部分：词汇练习1. supplier2. freight forwarder3. import regulations4. customs broker5. trade show6. distribution center7. inventory control8. product line9. marketing strategy10. online payment第二部分：阅读理解1. B – A trade show is an event where suppliers and buyers can meet face to face to discuss business.2. D – By attending trade shows, suppliers can showcase their products and meet potential buyers.3. C – Exporters might use a freight forwarder to handle shipping logistics and documentation.4. A – Customs brokers are responsible for ensuring that imported and exported goods comply with regulations.5. C – A distribution center is a central location from which products are stored and shipped to customers.第三部分：交际用语1. Would you like me to provide samples of our products before you make a purchasing decision?2. Can you tell me more about your shipping logistics process?3. We have a wide range of products available. How can I assist you in finding the right product for your target market?4. As a freight forwarder, we can handle all the logistics for you, including shipping, customs clearance, and delivery.5. We offer flexible payment options, including online payment and bank transfer.通过学习Unit4的答案，读者可以更好地理解和掌握跨境电商领域中的实用英语知识。
这些答案涵盖了Unit4的词汇练习、阅读理解和交际用语，读者可以通过在学习过程中与教材内容对照，更好地检验自己的学习成果和提升英语水平。
同时，这些答案也能为读者提供实际应用的参考，帮助他们更好地应对跨境电商实践中的交流和业务挑战。