The sentence
何をしてたと思う?
apparently translates to
What do you think I've been doing
Questions:
What is と doing here (and/or how is it literally being translated)? If we remove it, does the meaning of the sentence change?
According to a dictionary, "してた" is the past tense て form of する. But I thought the て form was "tenseless", and had to be combined with other verbs in order to achieve, e.g., the paste tense?