– I have got a headache. --No wonder. You in front of that computer too long. A. workB. a

问题补充：

– I have got a headache.

--No wonder. You in front of that computer too long.

A. work

B. are working

C. have been working

D. worked

答案：

(答案→)A. work

B. are working

C. have been working

D. worked

解析：考查时态。work和are working是一般现在时和现在进行时，只说明了现在的情况，而未包含过去的，故排除A和B；而worked只说明了过去，未包含现在，故排除D，只有C用了现在完成进行时，既包含了现在，又包含了过去，说明了动作对现在的影响是你头痛了，A是正确的。