A. at B. on C. in D. off
A. 合同标的、数量、质量 B. 合同价款或者报酬 C. 违约责任 D. 合同履行期限、履行地点和方式 E. 解决争议方法
A. considered B. regarded C. treated D. looked upon
A. treated B. trained C. traced D. transformed
A. whom B. that C. what D. which