31.—I have got a beadache. —No wonder. You in front of that computer too long.
(A)work
(B)are working
(C)have been working
(D)worked

本题考查动词时态。从句意“你在电脑前工作的时间太长”可知，动作从过去开始。一直延续到现在，可能还会继续延续下去，所以应用现在完成进行时。