It’s only six o’clock now; Little Tom should be up ,though, because he for nine hours.
A. has been sleeping
B. had been sleeping
C. has slept
D. had slept
网友回答
(答案→)A. has been sleeping
B. had been sleeping
C. has slept
D. had slept
解析：考查时态。句意：尽管现在只有六点；小汤姆应该起来了，因为他已经睡了九个小时。可知本句描述的是过去九个小时中一直在进行的动作，故用过去完成时态，选A。