Complete the tired college student's text message to her friend about her library mishap. Drag the right verb phrases to fill the gaps.

I was so embarrassed! I fell asleep right on my keyboard because I had been typing my history essay for six hours straight. By the time I finally woke up, I had drooled all over my notes.

I fell asleep right on my keyboard because I had been typing my history essay for six hours straight.

We use the Past Perfect Continuous (had been typing) to explain the cause of a past result (falling asleep). The typing started in the past and continued up until she fell asleep.

By the time I finally woke up, I had drooled all over my notes.

The phrase "by the time" introduces a completed event in the past, which takes the Simple Past (woke).