The application of law refers to the special activities of the national judicial organs in accordance with statutory powers and statutory procedures to specifically apply the law to handle cases,. According to the above definitions, is the following act applicable to the law? ['toms officer investigates Zhang as suspected of smuggling.', "The inspection authority investigated Wang's bribery behavior according to the mass reports.", 'Li signed a house sales contract with a sales department in accordance with relevant national laws and regulations.', 'Working conference held by the Director of Public Security and improving the quality of police handling cases.']