Use Passive Voice
Dinner always (cook) by my mother
What butter ( make) from?
The book (write) last year
When the Tower of London (build)?
The rainbow can (see) in the sky after rain

The rainbow can be seen in the sky after rain почему can be?

Потому что после can следует инфинитив без частицы to

thank you

Dinner is always cooked by my motherWhat is butter made from?The book was written last yearWhen was the Tower of London built?The rainbow can be seen in the sky after rain

Dinner is always (cooked) by my mother. What is butter ( made) from? The was book (written) last year. When was the Tower of London (built)? The rainbow can (seen) in the sky after rain.