问题补充：
- You look exhausted!
- I tennis with my friend all the morning.
A. played
B. had played
C. have been playing
D. will play
答案：
A. played
B. had played
(答案→)C. have been playing
D. will play
解析：考查时态。根据关键词all the morning可知这里是指一直在做某事，用完成进行时表示从过去某个时间开始到现在一直在做的事情。句意：我一直在和我的朋友打网球。
