Question

Which of the following is a sentence fragment?
a. Checking his mail each day was always fun.
b. Hiding in the tree fort he had built as a kid.
c. Realizing you are getting older is sobering.
d. Knowing he would be late, she took a nap.

Answer 1

The correct answer is B. Hiding in the tree fort he had built as a kid. 

This is a sentence fragment because on its own it has almost no meaning and requires clauses to be added in order to fully convey meaning.