A、The plane is safe even if two of its engines fail. B、There are three engines on each of the giant jet plane. C、There is an ext

Have you ever traveled on any of the giant jet airplanes? If you have not been a passenger on one of these planes, try to imagine a jet which is more than 70 meters long and more than 5 stories high at the tail. [22]Such a plane costs at least 25 million dollars to build. It costs at least $6,000 to fill this giant with fuel. [23]Inside, the jet looks more like a great theatre than a plane. It has 6 kitchens. They are all needed when the plane is full. The jet can hold more than 400 passengers. Imagine that number in one jet plane. Is there any danger that the jet’s engines will fail? Fortunately, the planes appear to be quite safe. On each plane, there are twice as many engines as it needs. [24]If two engines fail on the same side, the plane can easily use its other engines to land. [25]
    There are also two mechanical pilots to take charge, if the human pilots cannot fly the plane.
22. How much does it cost to build the giant jet?
23. What does the giant jet look like inside?
24. What do we learn about the engines of the giant jet plane?
25. What will happen if the human pilot cannot fly the plane?