4. Let LOVENSYSU be a string of 9 characters. How many different permutations of these characters such that the two S's are not adjacent? (A) 141120； (B) 362880； (C) 181440； (D) 40320.

複選題3. Suppose we have two functions fand g, withf(1)=3,f(2)=1,f(3)=4,f(4)=6, g(1)=5,g(2)=3,g(3) =4,g(4)=1,g(5) =3,and g(6) = 2. Which is the correct mapping of the composite function g o f? (A) go f(1) = 5； (B) go f(2) = 3； (C) go f(3) = 1； (D) g o f(4) = 6.