Complete the sentence with the correct option considering what you learned in lesson 8 - Narrative Tenses."
The burglar ______ to open the safe when he ______ the owner come in.
a. was trying / heard
b. tried / was hearing
c. tried / heard
The correct option to complete the sentence is:
a. was trying / heard
So the complete sentence would be: "The burglar was trying to open the safe when he heard the owner come in."