You define the following function in Python: def add(a, b, c):return a + b +...

1) a = 3; 2) b = a + 3; 3) c = a + b; 4) print(add(a, b, c))

The statements must be executed in dependency order. The function add(a, b, c) can be called only after values have been assigned to the variables that are passed as its three arguments. First, a must be set to 3. The next statement, b = a + 3, depends on a already existing, so it must follow the assignment to a. The statement c = a + b depends on both a and b, so it must be executed after b has been calculated. Finally, print(add(a, b, c)) can run only after a, b, and c all have valid values. With this order, a equals 3, b equals 6, and c equals 9. The function therefore returns 3 + 6 + 9, and print displays 18. Executing the statements in another order would attempt to reference an undefined variable and raise a NameError. The correct sequence is: a = 3, b = a + 3, c = a + b, then print(add(a, b, c)).