"What is the name of the bridge that opens in the middle?"Edit
This is Tower Bridge - not London Bridge. It is called so because it crosses the River Thames near the Tower of London. Tower Bridge was built in 1894. As an aside- there is a bridge called the London Bridge, and an American businessman purchased it, allegedly believing it to be the Tower Bridge.
"What is the river that flows through London?"Edit
It is the River Thames.
"Where does the Queen of England live?"Edit
The Queen's London residence is Buckingham Palace, located just south of Green Park. It is possible to visit the palace; St James's Park is the nearest underground station. The post code of Buckingham Palace was the first one ever issued, being SW1 1AA.