Many people today like reading stories about UFOs.Many people in different countries are 1._studying__ the UFOs.But what are UFOs?
There are some different saying for UFOs.2._Of__ those saying,the most popular one for UFOs is that they carry visitors coming from other stars.They 3._seem__ to fly much faster than planes to the earth.
UFO scientists and many people 4._believe__ this saying.Some people said that they saw a few UFOs that 5._had__ landed on earth.Some people said they saw some strange visitors coming out of the UFOs.Some even said they were carried away in the UFOs,and then were sent 6._back__ by the strange visitors.
Some people make mistakes when they say they have seen UFOs.7._Perhaps__ they see a weather 8._balloon__ or an uncommon plane,or the light they see in the sky comes from the ground.Sometimes they see the light from moon.
But there are a lot of things we can't 9.__understand_ .Now, people still can't understand UFOs clearly.It may take many years to find a clear 10._answers__ and then people will give UFOs another name.