Помогите пожалуйста 8 класс

При переводе из активного в пассивный залог не указывается агент, если в активном залоге в качестве подлежащего указывается: people, somebody, someone, one, THEY.
ПРИМЕР: People believe that garlic is good for health. – It is believed that garlic is good for health. (By people) - является излишним, САМО СОБОЙ РАЗУМЕЮЩИМСЯ и в предложении в страдательном залоге не пишется.
Соответственно, в 1, 4 и 6 предложениях "by them" НЕ НУЖНЫ!

1) A pie is normally baked in the oven.
2) A lot of preparations for my sister’s wedding have been made by my parents.
3) The secrets of international cuisine were learnt by us.
4) Some ingredients for the biggest pie in the world will be added.
5) Customers are being consulted by a shop assistant at the moment.
6) When I came home the sweets had been eaten.

Turn the following sentences into the Passive Voice.
(писать предложения сразу в пассиве)
1 A pie is normally baked in the oven with them
2 A lot of preparations for my sister’s wedding have been made by my parents
3 The secrets of international cuisine were learnt by us
4 Some ingredients for the biggest pie in the world will be added by them
5 Customers are being consultingated by a shop assistant this moment
6 When I came home the sweets had been eaten by them