Viết lại câu nghĩa ko đổi:
1. It is believed that she started the fire.
    She is believed........
2. I hope to receive a letter from my parents.
    I am loooking..........
3. It is overating that causes his heart ttack.
    If..........
4. Vitamin intake nd intelligence are not connected.
    There.........
Giải thích vì sao