Given database schema below, specify the following queries using relational algebra: TEACHER ID Name Degree Specialty Phone Street Add_num ZIP TEAM ASSIGNEDTO TID TNumber TNumber LeaderlD COURSE letter Level Name Tnumber PROJECT PNumber Name Topic Duration CLetter CLevel 1. Retrieve the name and ID of all "PhD" Teacher. 2. Retrieve the name of teachers who teache "Security" course. 3. For each leader find the name and the total numbers of teams that they lead. 4. Retrieve the name of courses that do not have any project. 5. Retrieve the number of projects for each course. 6. List the name and ID of the teachers, and the team number that they lead. 7. Retrieve the team number that contains all teacher. 8. Find the names of teachers that are lead by 'Sara Abdulaziz'. 9. Retrieve the team number that have the maximum number of teachers. 10. List the details of all teacher and include the team number that lead if any. 11. Retrieve the ID of all teachers either work in a team or lead a team