UFOs – do they exist?

UFO is short for ‘unidentified flying object’. UFOs are popularly known as flying saucers, (1) ................. that is often the (2) ................. they are reported to be.
The (3) .................. "flying saucers" were seen in 1947 by an American pilot, but experts who studied his claim decided it had been a trick of the light. Even people experienced at watching the sky, (4) ................. as pilots, report seeing UFOs.

In 1978 a pilot reported a collection of UFOs off the coast of New Zealand. A television (5) ................. went up with the pilot and filmed the UFOs. Scientists studying this phenomenon later discovered that in this case they were simply lights on boats out fishing.