Someone has taken my book away

→ My book has been taken away.

    He didn't help me with my homework.

→ I wasn't helped with my homework by him.

    We have learnt English for three years.

→ English has been learnt for three years by us.

    My father often reads books before bedtime.

→ Books are often read by my father before bedtime.

    Lan bought some comic books for her brother.

→ Some comic books were bought for her brother by Lan.

    My sister received a letter yesterday.

→ A letter was received by my sister yesterday.

    She can solve the problem in just 2 minutes.

→ The problem can be solved in just 2 minutes.

    Nowadays people use electricity for lighting.

→ Electricity is used for lighting nowadays.

1, Someone has taken my book away

⇒ My book has been taken away by someone

2, He didn't help me with my homework

⇒ I wasn't helped with my homework by him 

3, We have learnt English for three years

⇒ English has been learnt for 3 years by us

4, My father often reads books before bedtime

⇒ Books are often read before bedtime by my father

5, Lan bought some comic books for her brother

⇒ Some comic books were bought for Lan's brother by her.

6, My sister received a letter yesterday

⇒ A letter was received yesterday by my sister

7, She can solve the problem in just 2 minutes

⇒ The problem can be solved in just 2 minutes by her

8, Nowadays people use electricity for lighting

⇒ Nowadays electricity is used for lighting by people.