—Could you please tell me ?--Sure there is a post office at the end of the road .A. how

问题补充：

—Could you please tell me ?

--Sure , there is a post office at the end of the road .

A. how can I buy some stamps

B. where I can buy some stamps

C. where I could buy some stamps

D. how could I buy some stamps

答案：

A. how can I buy some stamps

(答案→)B. where I can buy some stamps

C. where I could buy some stamps

D. how could I buy some stamps

解析：此题重点考查宾语从句的时态和语序问题，无论哪种句式结构充当宾语从句都要用陈述句语序，从句的时态要和主句的时态保持一致。Could在此处表示语气而不是时态。