The past perfect progressive is a tense that we use when we are talking about events that have ended (perfect) but which are continuous to each other. It's very common in storytelling (like here).
In most cases in English, we show the perfect by using verbs that end in -ed.
Walked, Jumped, Asked, etc. A lot of English verbs are irregular in the perfect tense however. The perfect form of Eat is Ate, Fight is Fought, Sleep is Slept, and so on. In this exercise, you need to take the verbs in the brackets after each space and then make them into the perfect form.

The first one (prepare) is 'prepared', most of the rest follow that form, but (give), (leave) and (shine) are irregular and don't end in -ed like most English verbs would. Instead the perfect form of each is 'gave', 'left' and 'shone'.