— Are these your keys?— .A. Yes these areB. No these isn’t C. Yes they areD. No they i

问题补充：

— Are these your keys?

— .

A. Yes, these are

B. No, these isn’t

C. Yes, they are

D. No, they isn’t

答案：

A. Yes, these are

B. No, these isn’t

(答案→)C. Yes, they are

D. No, they isn’t

解析：本题为一般疑问句，回答语是肯定回答用yes，人称代词+肯定结构，本题应写成they are，故本题选C。