Bonjour,
Réponse :
a. Paul and I were eating Indian food and Lucy was texting her mum.
b. What were you doing last Sunday at 10 a.m.?
c. On that day, they weren't traveling by train. They were hitchhiking.
d. It was raining and she was trekking up to the summit.
e. I was looking at the scenery and around me everybody was taking pictures.
Explications :
Prétérit BE + V-ing = was / were + V-ing
I / He / She / It was
You / We / They were