Viết lại câu sao cho nghĩa không đổi

----- Nội dung dịch tự động từ ảnh -----
18. Someone has taken my book away.
-> My book
19. He didn't help me with my homework.
-> I
20. We have learnt English for three years.
-> English
21. My father often reads books before bedtime.
-> Books
22. Lan bought some comic books for her brother.
-> Some comic books
23. My sister received a letter yesterday
-> A letter ......
24. She can solve the problem in just 2 minutes.
-> The problem ....
25. Nowadays people use electricity for lighting.
-> Electricity .....