Замените they в предложении they are five boys in my class

There are five boys in my class

As soon as you come to london,  take a ride on the river  boat along the thames. in case you go to st. petersburg in june, you will be able to see the white nights there. provided  you cross the ural mountains, you will be able to visit asia. before you start planning a trip to canada,  read about its rivers, the great lakes, the niagara falls and about the capital of the state the city of ottawa. after you arrive to irkutsk, you will be able to see lake baikal. if you want to have a look at the alps,  go to central europe. the mountains are located in three countries: italy, france and switzerland. when you arrive to the british islands, you'll be able to get acquainted with four countries: england, wales, scotland and ireland.

The most important thing is balance and variety. when you’re training, your body needs lots of different things so you must eat different kinds of food. you should eat lots of fresh fruit and vegetables because they give you lots of vitamins, especially vitamin c which is important.  you should eat bread, potatoes and pasta. all these things give you carbohydrates. but you mustn’t eat too many sweets or chocolates because you’ll put on weight and they’re bad for your teeth.  finally, protein is important when you’re training. for protein you must eat meat and vegetables, like beans. you should also eat plenty of eggs and milk. eggs and milk also give you calcium which is important for your bones.  one other thing – you must eat regularly every day. you mustn’t eat your meals at different times, for example, or eat a lot one day and a little the next.  you should also have a good breakfast and you shouldn’t eat too much before training, it’s very bad for you.  i nearly forgot: when you’re training, you must never smoke cigarettes!