me what you wanted to know I should not have wasted my time talking so much with you.A.

问题补充：

me what you wanted to know, I should not have wasted my time talking so much with you.

A. Had you told

B. You have told

C. You had told

D. Have you told

答案：

(答案→)A. Had you told

B. You have told

C. You had told

D. Have you told

解析：A 考察虚拟语气和特殊句式。句义：如果你早告诉我你想知道的事情，那么我就不会浪费时间和你说这么多了。由句义可知，这是对过去事情的虚拟，所以主句使用should have done，从句相应地使用过去完成时。故A正确。