Kate and I doing homework now.A. am theirB. are theirC. is ourD. are our

问题补充：

Kate and I doing homework now.

A. am, their

B. are, their

C. is, our

D. are, our

答案：

A. am, their

B. are, their

C. is, our

(答案→)D. are, our

解析：此题重点考查现在进行时的构成和形容词性的物主代词。我和Kate是复数即相对应的物主代词是their。