Past continuous and past simple
I _____ so I _____ the question. (not listen / not hear)
I wasn't listening so I didn't hear the question.
We ______ in the park when we ______ the fox. (walk / see)
We were walking in the park when we saw the fox.
They ________ in a cafe when he _______ her to marry him. (sit / ask)
They were sitting in a cafe when he asked her to marry him.