I am studying past simple and past continuous and then encountered an exercise(filling the blank with the words in parentheses in correct tense) as below:
Last night, while I was doing my homework, Angela (call) called. She said she (call) was calling me on her cell phone from her biology classroom at UCLA...
The bold texts are correct answers. I have no problem of the first one, it indicates a longer action was interrupted (by a shorter one). But the second answer uses the past continuous and I couldn't understand it. I could not figure out which usage of past continuous it belongs to. Could anyone help explaining? I learned the 5 usages of past continuous from English Page(http://www.englishpage.com/verbpage/pastcontinuous.html). Thanks for your time and effort!