Consider the following database schema that keeps track of student enrollment in courses and the books adopted for each course: ENROLL (ID, Course#, Semester, Grade) BOOK_ADOPTION (Course#, Semester, Book_ISBN) TEXT (Book_ISBN, Book_Title, Publisher, Author) Answer the following questions: 1) Use SQL command(s) to add the textbook titled fundamentals of database systems. The book has 110112345 as an ISBN No. and published by McGraw Hill. Then adopt this book for the course# ES325 during the semester Spring 2011. 2) Put the Grade 85 to the student with ID 123456 in the Course# ES325 during the Semester Spring 2011. 3) Retrieve the book-title and course# for the courses offered during the semester "Spring 2011". 4) During 'Fall 2010', retrieve the average Grade for each course and the number of students who enrolled in these courses. 5) During 'Fall 2010', retrieve the sum of Grades for each student in all courses in which the student is enrolled.