当问题重大、确急需直接上级和更高层次的上级机关同时了解公文内容时,可采用直接行文的方式。( )
参考答案:错
The company's profit drop _____ in the last three months of 2009 due to the financial crisis. [ ]
A. narrowly
B. sharply
C. roughly
D widely
公钥加密系统的基本组成元素是什么?