Question 1：
  Which of the following is always produced when a SAS program excutes?
A a log that contains messages about the program
B procedure output
C an interactive window

思考下，答案来了。。。。。。
   A Correct---SAS programs always produce a log.Depending on the program submitted,it can also produce output or open a window.
   B Incorrect---SAS program don't necessarily produce procedure output,althought many do.Some programs only produce messages in the log or take you to an interactive window.
   C Incorrect---Many SAS programs produce results in the form of messages in the log or procedure output,without taking you to an interactive window.