Question

They were knocking at the door.
My brother was helping them.
Your sister was learning her lesson.

Answer 1

1⃣The door was being knocked by them .
2⃣They were being helped by my brother .
3⃣Her lesson was being learnt by your sister

Answer 2

⛦Hᴇʀᴇ Is Yoᴜʀ Aɴsᴡᴇʀ⚑
▬▬▬▬▬▬▬▬▬▬▬▬☟

❖ Question is:-
=======================⤵
[1] They were knocking at the door.

[2] My brother was helping them.

[3] Your sister was learning her lesson.

▶ So, Answer is:-
=======================⤵

[1] The door was knocked by them.

[2] They were being helped by my brother.

[3] Her lesson was being learnt by your sister.

_________
Thanks...✊