1 if you are tired of walking about London, you can get on a bus.
2 if you are lucky enough to find yourself in London some day you will have a lot to see and enjoy there.
3 If you plan to travel extensive by bus and underground in London you will ask at your nearest British International Travel Office.
4 If there is place I want to visit, it will be definitely London.
5 If you are tired of London you will be tired of life.
6 She will call you if she has time.
7 If it costs too much, I will buy a smaller one.
8 I will go next week, If I can get a train ticket.
9 If it snows this winter, we will go skiing.
10 If you visit Oxford, you will see some interesting old buildings.