所谓PKI就是一个以公钥技术为基础的，提供和实施安全服务的具有普适性的安全基础设施。

e soldiers soon reched ______ ws oncen old temple ______ the villgers useds school.wht ; where B．wht ; which C．where ; which D．wht ; whereA．what ; whereB．what ; whichC．where ; whichD．what ; where