Complete the sentences with the correct forms of the verbs in the brackets. Use the past perfect continuous.

1.  I did not go out last night because I (work) [ ] all day.

Рис. \(1\). Working

2.  When John became an actor, he (study) [ ] drama for five years.

3.  The passengers (wait) [ ] for four hours before the ground staff could finally give them information on the delay of their flight.

4.  She (learn) [ ] Spanish at school.

Рис. \(2\). Spanish