单选题 Virtually every theory has been concerned with either the structure or the function of the language.
A．Vertically B．Almost C．Actually D．Finally

【正确答案】 C

【答案解析】[解析] 副词辨析
Virtually表：事实上，实质上；而选项A．Vertically垂直地；B．Almost几乎，差不多；C．Actually实际上，事实上，竟然；D．Finally最后，终于，决定性地；因此C为答案。