حل تشریحی سوال شماره 20 زبان تخصصی (انگلیسی)

PART C: Reading Comprehension Directions: Read the following three passages and answer the questions by choosing the best choice (1), (2), (3), or (4). Then mark the correct choice on your answer sheet. PASSAGE 2: A CAPTCHA prevents bots from filling out and submitting a public form on a website. A common type of CAPTCHA requires the user to type letters and/or digits from a distorted image that appears on the screen. CAPTCHAs are used in attempts to prevent automated software from performing actions, which degrade the service quality of a given system, whether due to abuse or resource expenditure. The process usually involves a computer asking a user to complete a simple test which the computer is able to grade. These tests are designed to be easy for a computer to generate but difficult for a computer to solve, but again easy for a human being. Since thousands of hours are spent daily solving CAPTCHAs, it can be used as a new technique to promote company products or websites. In CAPTCHA advertising, users typically type in brand messages instead of distorted text. In today's technology, benefits of CAPTCHAs are twofold: website security and advertising