—Sandy,Icalledyouat9：00lastnight,butnobodyansweredtheph...

问题详情：

—Sandy, I called you at 9：00 last night, but nobody answered the phone.

       —I'm ________ a birthday party for Jerry.

                     having  

        having      have

【回答】

B

知识点：动词时态

题型：选择题