选择题：Early this year,Captain Startup was flying an aero

Early this year,Captain Startup was flying an aeroplane over New Zealand.There was a television
camera crew on board.Suddenly,out in the night sky,a bright sphere came into view.Everyone on
board saw it and everyone thought,"UFO"-Unidentified Flying Object.Many people believe that a UFO is a visiting craft from outer space.The camera crew went into action and started filming.That week people all over the world saw the film of this mysterious light on their television screens.Someone described the object as"a shining ping-pong ball".What was it?Was it a spaceship full of visitors from another planet?The Captain and the film crew believed it was.Other observers had many different explanations.Some say it was Venus.Some say it was just a trick of light.The people on the aeroplane were not the only ones who saw the"UFO".An air traffic controller also saw it on his radar Screen.When a reporter asked him if he believed in UFOs,he said,"I don.t know what they are,but I.ve got an open mind on them."Like many scientists,he thought that a flock of birds caused dots on his radar screen when the UFO appeared.
Most astronomers now believe that what these people saw was almost certainly the planet Venus.At that time of year it is very bright and easy to see.And from a moving aeroplane it can appear to be moving fast.So far there is no proof that UFOs or spaceships from other planets do ex