question: How many credits is the course that the student with the last name Smithson took, and what is its description?
#1 return students 
#2 return last names of  #1 
#3 return #1 where  #2 is  Smithson 
#4 return courses of  #3 
#5 return credits of  #4 
#6 return description of  #4 
#7 return #5 ,   #6