合成系统压力增大，流量降低的主要原因是（）。
A.水碱洗系统阻力增大
B.预热器渗漏
C.转化器渗漏
D.HCl大量过量
参考答案：A
Kerberos协议用于认证用户对网络资源的请求，执行用户和服务的安全确认的是 ( )。
A．发送方
B．接收方
C．可信任的第三方
D．双方
The main function of a processor is to (68) and carry out instructions which usually consist of operation and (69) . The term to measure the speed of the processor is called a Megahertz (MHz), which means million (70) per second.
A．bits
B．bytes
C．cycles
D．words
