短文填词。

     阅读下面短文，根据以下要求：(1)汉语提示；(2)首字母提示；(3)语境提示，在每个空格内填入

一个适当的英语单词，所填单词要求意义准确、拼写正确。

     The college entrance exam is on the way and all the teachers work very hard, encouraging us to build

(1)_____ our confidence and inspiring us to (2)i_____ our studies. Whenever we meet with difficulties,

they are (3)r to come to our help. Meanwhile, our school also (4)_____ (提供) great help for us students,

for example, the library stays (5)_____ in the evenings and even on the weekends. At home, our parents

take good care of (6)_____ so that we can always be full of energy. I'm very grateful for the (7)_____ (努

力) of our parents and teachers. I'm (8)_____ (决心) to try my best to prepare for the exam. I am sure that

(9)w_____ their timely help I'll be able to achieve my goal and be a useful person of our society in the near

(10)f_____.

基于通信双方共同拥有的但是不为别人知道的秘密，利用计算机强大的计算能力，以该秘密作为加密和解密的密钥的认证是（）。

A.公钥认证

B.零知识认证

C.共享密钥认证

D.口令认证