完形填空。 Many people today like reading stories about UFOs. Many people in different countries are 1 UFOs. But what are UFOs? There are some different ideas about UFOs. 2 popular one is that UFOs carried visitors coming from other stars.They 3 to fly much faster than planes on the earth. UFO scientists and many other people believed it.Some people said that they saw a few UFOs 4 on the earth;some people said they saw some strange visitors 5 the UFOs; others even said they were taken 6 in the UFOs,and then were sent back. Some people made mistakes (犯错误) when they said they ever saw UFOs. They 7 saw a weather balloon(气球) or a plane,or the light in the sky(天空) 8 the ground. Sometimes it is the light from the moon. But there are a lot of other things we can't understand. Now people cannot see UFOs clearly 9 .It may 10 many years to find a clear answer. Then people will give the UFO another name. (     )1. A. seeing (     )2. A. The more (     )3. A.looked (     )4. A .fall (     )5. A. coming into (     )6. A. off (     )7. A.must (     )8. A.of (     )9. A.yet (     )10.A.spend B. hearing B. Most B. seemed B. fly B. coming out B. down B. could B. around B. already B. take C. studying C. More C. happened C. take off C. coming out of C. away C. probably C. from C. even C. pay D. following D. The most D. failed D. land D. getting out D. up D. may D. on D. also D. pay for