计算机网络安全是指( )。
A．网络中设备设置环境安全
B．网络使用者的安全
C．网络中可共享资源的安全
D．网络中财产的安全
参考答案：C
根据下列句子的意思，用括号中所给词的正确形式填空，每空限填一词。
1. President Hu Jintao _______ (fly) to the earthquake-hit region in Yushu, Qinghai on April 18,2010.
2. I'm _______ (feel) terrible today, so my mother will take me to see a doctor.
3. The compass helped people make many ________ (discover) in the past.
4. He held a glass with care, because he was afraid of _______ (break) it.
5. Our village has developed ______ (rapid) now, our life is becoming better and better.
读图，回答。
写出地震波名称：C（）D（）。
