问题
选择题
Lisa, now stop for a short break. You should know that you all the morning.
A．are working
B．had been working
C．have been working
D．have worked
答案
答案：C
考查动词时态。根据now stop for a short break，可知现在还在工作，再根据all the morning，可知整个早晨一直在工作，所以要用现在完成进行时态，表示从过去开始到现在一直在进行的动作。有可能还会进行下去。所以选C。