1. укажите have/has: the railroads a switch which is a very important element of the track. 2. укажите is/are: the track one of the basic feature of a railway. 3. укажите do/does/am/are/is: the development of a country depend on transport? 4. укажите doesn't/ don't/aren't/isn't/am not: if the engine efficient, the losses of energy are large. 5. задайте вопросы к предложению: the choice of the monorail type depends upon climatic conditions, the territory, the number of passengers and so on.