搜题请搜索小程序“爱下问搜题”
问题 问答题 简答题

热水锅炉运行由什么特点？

答案

参考答案：

1、出水温度要求比相应压力下的饱和温度低20℃，以防汽化；

2、锅炉恒压是靠循环泵来保持的；

3、低温腐蚀和汽化水击是热水锅炉易发生的故障。

单项选择题

Pharming is a scamming practice in which malicious code is installed on a personal computer or server, misdirecting users to (1) fraudulent Web sites without their knowledge or consent. Pharming has been called "phishing without a lure".

In phishing, the perpetrator sends out legitimate- (2) looking e-malls, 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 (3) victimized 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 (4) bookmark entry. Some spyware removal programs can correct the corruption, but it frequently recurs unless the user changes browsing. (5) habits,

5（）

A．habits signature

B．site

C．rages

D．address
查看答案
单项选择题

某公司将其使用在皮包上面的“雪花”商标再次注册在其生产的皮鞋、皮裤之上，这种商标称为( )。

A．集体商标

B．联合商标

C．防御商标

D．证明商标
查看答案