Past perfect continuous

The students _______ for hours before the exam began.

• Had studied

• had been studying

• Have been studying

I _________regularly, so I wasn't in good shape for the race.

• hadn't been exercising

• had been exercising

• had never been exercising

_____ you _________ on this project before you joined our team?

• have..... been working

• had.... done working

• had.... been working

My sister __________the piano all morning when I arrived.

• had be practicing

• have been practicing

• had been practicing

The company _____________ in research and development, which hurt its competitiveness.

• hadn't been investing

• haven't been investing

• hadn't done investing

How long ______the restaurant ________ sushi before they added a new menu item?

• has.........been serving

• have......been serving

• had.....been serving

The construction workers ___________the bridge for six months before it was completed.

• have been building

• had been building

• haven't been building

The children _____________ attention in class, so they didn't understand the lesson.

• hadn't been paying

• haven't been paying

• wasn't been paying

_____the doctors ___________your blood pressure during your hospital stay?

• had........ been monitoring

• have........been monitoring

• have..........being monitoring

The team _____________hard for weeks before the championship game.

• has been training

• have been training

• had been train

• had been training