The little boy is dirty from head to foot because he in the mud all morning.A. has played

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。