выбрать правильные Are these sentences right or wrong?

1. An operator can know how to use the telephone system. An operator may know how to use the telephone system. An operator should know how to use the telephone system.
2. I suggest we should buy a mobile telephone to stay in touch. I suggest we bought a mobile telephone to stay in touch. I suggest to buy a mobile telephone to stay in touch.
3. If Tom called leave me a message. Should Tom called leave me a message. Must Tom called leave me a message.
4. You should deal with the calls promptly in the morning but I see that they are not answered. You should have dealt with the calls promptly in the morning but I see that they are not answered. You should be dealing with the calls promptly in the morning but I see that they are not answered.

London

London is the biggest city in Britain.Over seven million people live and work in london.

London is also ane of the most important cities in the world.It is a centre for business and tourism.

There are many exciting things to do in London.the city has got some of the best theatres and museums in the world.There are a lot of places to go at night.It is a fun city.

In London you are never far from the River Thames.many tourists go on bout trips from Tower Bridge to Westminster.

Another good boat trip is to Greenwich.In Greenwich you can visit The Old Royal Observatory.The boat passes a lot of famous buildings.

Palaces

Buckingham palace is the london home of the Queen.you can walk from Westminster Abbey to the palace.It is a pleasant walk through St James's Park.

Soldiers always guard the palace.At half past eleven every morning , you can watch the soldiers change guard.

The Queen's Gallery is in Buckingham palace.You can visit the gallery and see the Queen's collection of paintings.

Another of the Queen's homes is Windsor Castle . Windsor is near the River  Thames, about forty kilometres from London.The castle is eight handred years old.

1. Oleg said that his room was on the second floor

2. He said he was sure she would ring him up when she was back in St Petersburg

3. Mishap said he saw them at his parents house 2 years ago

4. He said he hadn’t seen his cousin yesterday

5. She said she didn’t go to that shop very often

6. Tom said he had already had breakfast so he wasn’t hungry

7. He said he had just received a letter from his uncle

8. He said to me he was going to the theater that night.

9. Mike said that he had spoken to Mr Brown that morning

10. He said to her that he would do it yesterday if he had time

11. I said to them that I could give them my uncles address