不属于计算机防毒措施的是()
A、制作和系统启的盘
B、重要磁盘保护
C、备份
D、系统升级
参考答案：D
When we returned from the ball, we found that our house ___ and many things __
A．has broken into; has been stolen
B．has broken into; had been stolen
C．had been broken into; stolen
D．had been broken; stolen
简述针刺刺伤脑脊髓的原因、临床表现和预防。
