Read these sentences and fill in the gaps with the correct verb form in the past perfect continuous. Example 0. John his dog all day. He was tired yesterday. (walk)

Answer 0. had been walking.

1. Her friends
of calling the police when she walked in. (think)

2. I was exhausted because I
awake too late. (stay)

3. She
English for four years. It was exciting. (learn)