Here's the completed dialogue with the Past Continuous forms of the verbs:
Marge: Where were you and Mac this morning, Eva? I ¹was looking for you, but you ²weren't answering your phones.
Eva: Sorry, Marge! I ³was reading some old books about Egyptian History at the library.
Marge: Was Mac at the library too?
Eva: No, he wasn't. He ⁴was helping Pops in the garage, so he didn't hear the phone.
Marge: What ⁵were they doing in there?
Eva: They ⁶were packing the car for our next adventure.