问题补充：
—Linda, I called you this morning, but nobody answered the phone.
—I’m sorry. I football with my friends then.
A. play
B. played
C. am playing
D. was playing
答案：
A. play
B. played
C. am playing
(答案→)D. was playing
解析：
试题分析: 句意：琳达，今天上午我打电话给你了，但是没人接电话。对不起，我当时和朋友在踢足球。then当时，根据语境可知是过去进行时，故选D
