以下关于接力切换、硬切换、软切换说法错误的是（）A、接力切换有预同步过程； B、硬切

有以下程序　　main(　)　　{　union{　unsigned int n;　　　　　　　unsigned char c;　　　　　　}ul;　　　ul.c=''A'';　　　printf("%c\n",ul.n);　　}　　执行后输出结果是（ ）。

A． 产生语法错

B． 随机值

C． A

D．65

气体灭火系统的管道及管道附件应符合下列规定：（）。

A、输送气体灭火剂的管道应采用无缝钢管

B、输送气体灭火剂的管道安装在腐蚀性较大的环境里，宜采用不锈钢管

C、输送启动气体的管道，宜采用铜管

D、管道的连接，当公称直径小于或等于80mm时，宜采用螺纹连接；大于80mm时，宜采用法兰连接

Pharming is a scamming practice in which malicious code is installed on a personal computer or server, misdirecting users to (71) Web sites without their knowledge or consent. Pharming has been called "phishing without a lure".
In phishing, the perpetrator sends out legitimate- (72) e-mails, appearing to come from some of the Web’s most popular sites, in an effort to obtain personal and financial information from individual recipients. But in pharming, larger numbers of computer users can be (73) because it is not necessary to target individuals one by one and no conscious action is required on the part of the victim. In one form of pharming attack, code sent in an e-mail modifies local host files on a personal computer. The host files convert URLs into the number strings that the computer uses to access Web sites. A computer with a compromised host file will go to the fake Web site even if a user types in the correct Internet address or clicks on an affected (74) entry. Some spyware removal programs can correct the corruption, but it frequently recurs unless the user changes browsing ( 75 ) .

A．few

B．fraudulent

C．normal

D．structured

标准天然圆钻腰围通常是“糖化”的，称为（）。

A.抛光腰

B.粗磨腰

C.刻面腰

D.波状腰

对于恒转矩负载，为什么调压调速的调速范围不大？电机机械特性越软调速范围越大吗？