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

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

4（）

A.hypertext 

B.computation 

C.expectation 

D.bookmark

纯度是指色彩的（）程度，又称饱和度。

A、深浅度

B、亮度

C、明度

D、鲜艳度