Indirect principal offense: Refers to using another person as a tool to commit a crime, and there is no joint crime with the victim. Which of the following are indirect principals? ['In a burglary case, a certain person was only responsible for watching the wind and did not implement specific theft.', 'A preplans to kill a patient and finds ways to deliver the poison to an unsuspecting nurse.', 'A sells the jewelry obtained from the robbery to an unsuspecting acquirer.', 'Someone sends illegally obtained photos to netizens for circulation.']