_____ many times, but he still couldn't understand it. [ ]

A. Though he had been told

B. Having been told

C. Having told

D. He had been told

从本质上说，国家是（）。

A.管理社会公共事务的机关

B.立法、司法、行政机关的总和

C.社会发展到一定历史阶段的产物

D.经济上占统治地位的阶级进行阶级统治的工具