Freelancers refer to people who transform their wisdom, knowledge, ability, and experience into actual benefits through the Internet. They solve problems in science, technology, work, life, and learning on the Internet to make knowledge, wisdom, experience, and skills. Reflecting economic value. According to the above definitions, Which of the following sites that belong to Freelancer or Freelancer Mode are (). ['A website provides the search of academic papers for nearly thirty years, but a certain fee will be charged if you want to download the full text.', 'Professor Zhao is a well-known expert in the treatment of cardiovascular and cerebrovascular diseases. To serve a wider range of patients, he has created a personal web page on the Internet to provide free professional consultation for patients with cardiovascular and cerebrovascular diseases. The hospital has increased its visibility and attracted more patients to seek medical treatment.', 'A large home appliance manufacturing company has launched its own website. Consumers can leave addresses and contact information on the Internet if they encounter any problems in the process of using the home appliances produced by the company. The company provides on-site services.', 'This year, there has been a kind of website that has quietly risen on the Internet. Task publishers can post tasks on the website and prepay the task bonus in full to the website. The task attracts many netizens to participate in the task, and the website will receive some bonuses. Pay to the best performing participant.']