Перефразируйте следующие предложения,используя конструкцию complex object.

 1. I believe they are very good at physics and other pure sciences.

2. when he opened the window he heard how the birds were singing in the garden.

3. I heard that his name was mentioned several times during the conversation.

4. I saw that he opened the door and the left the room. 

complex object - сложное дополнение. существительное или местоимение плюс инфинитив без to.

1- I believe them be very good at physics and other pure sciences.

2- when he opened the window  he heard the birds be singing in the garden.

3- i heard his name be mentioned several times during the conversation.

4- i saw him open the door and leave the room.