✔ Two Past Actions (Earlier + Later) + Time reference→ Past Perfect Continuous + Simple Past [Example: She had been working at the company for five years before she resigned. /They had been arguing since morning before they reached an agreement.]
1. She (study) for three hours before her friend arrived.
See Answer2. They (play) football for two hours before it started raining.
See Answer3. I (work ) on the project for a week before I submitted it.
See Answer