论述题 解释下面哪些商品和服务是可贸易或不可贸易的。有没有你的答案不成立的特殊情况? a．水泥；b．汽车；c．面包；d．银行的数据处理服务；e．铜。 Explain whether the following goods and services are tradable or non—tradable．Are there special circumstances in which your answer does not hold? a．Cement；b．Cars；c．Bread；d．Dater processing services for a bank；e．Copper．