I was busy cooking dinner when you called me earlier.

I was busy studying for my exam all night long.

I was busy typing up a report for work when my computer crashed.

I was busy practicing my guitar skills for the upcoming concert.

I was busy cleaning the house before my guests arrived.

I was busy working on a new painting in my art studio.

I was busy organizing my closet and getting rid of old clothes.

I was busy preparing for my job interview the next day.

I was busy taking care of my sick child who was home from school.

I was busy exercising at the gym to stay fit and healthy.