Internet addiction: refers to a type of mental behavior disorder caused by an individual's repeated excessive use of the Internet, which is manifested by a strong desire to use the Internet, sudden cessation or reduced use of irritability, inattention, sleep disturbance, etc. Which of the following behavioral symptoms of Internet addiction are:. ["After Li Xiaobing's college entrance examination, his parents stopped questioning the Internet, and he felt mental as long as he was not online.", 'Student Zhang works diligently and works as an administrator for an Internet cafe. He spends all his spare time in Internet cafes and often lacks sleep.', 'The sales manager of a company spends all day online, contacting customers, processing orders, and the pressure of work makes him a little irritable.', 'Several students of e-commerce majors from a vocational and technical college opened an e-shopping website in partnership. The business was hot and there was almost no time to go offline. The teacher said that they had snacks in class.']