Понимание структурно-смысловых связей в тексте

When you mention the name ‘Hovercraft’, most people think of a helicopter. If someone sees one from the river bank, the term ‘airboat’ comes to their mind because most people are not quite sure A ______. Few people know of the personal sized hovercraft B ______.

A hovercraft is a vehicle, designed to travel over any smooth surface. Hovercraft is unique among all forms of transportation in their ability to travel equally well over land, ice, and water C ______. That is why they are used throughout the world as a means of specialized transport D ______. Hovercraft can be powered by one or more engines. The engine drives the fan, which is responsible for creating high pressure air. The air inflates the ‘skirt’ under the vehicle, causing it to rise above the ground.

The Hovercraft Museum, located in Hampshire, houses the world’s largest library of documents, publications, photographs and drawings on hovercraft, E ______.

The museum also contains a large collection of original manufacturer’s hovercraft models including the world’s first working hovercraft model built by Christopher Cockerell.

Cockerell’s idea was to build a vehicle floating on a layer of air, F ______. To test his hypothesis, he put one smaller can inside a larger can and used a hairdryer to blow air into them. Christopher Cockerell was knighted for his achievement in 1969.

Hovercraft have now become much larger, more efficient and are in widespread use all over the world.

1. all of which are available for research
2. where there is the need to travel over multiple types of surfaces
3. what they are looking at
4. which would reduce friction between the water and vehicle
5. so as to entertain the general public
6. that are used worldwide for recreation, racing and rescue
7. because they are supported by a cushion of air