问题补充:
The little boy is dirty from head to foot because he in the mud all morning.
A. has played
B. is playing
C. has been playing
D. was playing
答案:
A. has played
B. is playing
(答案→)C. has been playing
D. was playing
解析:提示:由“…is dirty”和“all morning”可知,小孩一直在玩。过去的动作一直延续到现在并且还在进行应用现在完成进行时表示。