Final answer:
The underlined verb phrase 'had been dreaming' is in the perfect continuous past tense, indicating an ongoing action in the past.
Step-by-step explanation:
The tense used in the underlined verb phrase 'had been dreaming' is perfect continuous past tense. This tense is formed by combining the past perfect tense (had + past participle) with the present participle of the main verb (been + -ing). It is used to describe an ongoing action that started in the past and continued up until another past event (in this case, being woken up).
For example, in the sentence 'I had been studying for hours when my friend called,' the action of studying had started in the past and was ongoing until the friend called in the past.
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