题型：问答题 论述题 根据下面的对话内容，从方框内的选项中选出最佳选项，选项中有一个为多余选项。 M: Oh, hi, What is your name again? Since this is only the 2nd day of school, I can't remember the students' names yet. W: 1.________ I have a hard time remembering names myself. M: Uh, Karen, right? W: 2.________ My mom's name is Karen. M: Nancy, Okay. I think I heard you were from England. W: Well, I was born there, but my parents are American. I grew up in France. M: 3._________ W: But then we moved here when I was nine. M: 4.________ W: Well, he is a college professor, and he is in Scotland at the moment. M: How interesting! What does he teach? W: Oh, I have no idea. 5._______He teaches chemistry. A. So, what does your father do now? B. It is okay. C. Nah, just joking. D. What's your mother's name? E. Oh, a world traveler! F. No, it is Nancy. 查看答案
题型：问答题 论述题 DES密码体制的算法基础是 (42) 。这是一种分组密码，分组的长度为 (43) 。这种算法中，密钥的分配和安全管理对确保密码的秘密是至关重要的。当有n个人互相进行通信时，总共需要 (44) 个密钥。而公开密钥体制可以把加密密钥公开，所以在n个人相互通信的系统中只需秘密管理 (45) 个密钥。RSA是一种公开密钥体制，其算法基础是 (46) 。A．nB．n2C．n(n-1)/2D．2n 查看答案