Answer:
When a sentinel is used in a (pretest/post test) loop to validate data, the loop repeats as long as the input is (valid/invalid).
Explanation:
Required
Fill in the gaps
Sentinel are used to validate or invalidate loops (pretest and post test loops).
Since , some parts of the brackets have aready been filled, we simply complete the blanks with the opposite of the term in the bracket. i.e. the opposite of post test is pretest and the opposite of valid is invalid.
So, the blanks will be filled with pretest and invalid.
