单选：既能息风止痉，又能祛风湿，止痹痛的药物是：（）A．羚羊角B．石决明C．决明子D．天麻E．珍珠

下列关于卫星导航系统的表述不正确的是：A．GPS的信号强度与准度是可控的B．GPS是欧盟建立的卫星导航系统C．北斗导航系统是我国自主研发的卫星导航系统D．“伽利略”导航系统是第一个基于民用的全球卫星导航系统

Never before in her life has Helen seen such beautiful and precious jewelry.

Our textbooks are very different from theirs.

Please tell me what to do next.

传统管理信息系统开发方法有哪些问题。