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Row Class Sid# Student Name Test#1 raw Pid# Test#1 Total Professor Test#1 extra % Office# Test#1 extra credits 1 1 AIC 10 5 55 2 Gauss 22 2 1 2 Bob B 60 10 6 66 2 Gauss 22 3 2 3 Cal T 70 10 3 77 Jay 33 2 4 Dan P 80 10 8 3 Jay 33 5 3 5 EdP 10 3 Jay 33 6 3 3 Cal T 10 99 Jay 34 The table is from a file has a record of all student's information including name, Id, scores and their assigned professor for each class. 1. List those with any NULL value? 2. Among all with NULL, what missing information is required or necessary? 3. Among all with NULL, what can be derived