1.I/ believe/UFOs/exist/because/articles/reports/talk/lots/their appearance

=> i believe UFO are existed because article reports talk lots about their appearance ( n/ diện mạo ) 
2.Firstly/There/plenty/photos/them

=> firstly there are plenty photos of them 
3.Secondly/many people/say/they/see/man-like creatures/get out/UFOs.

=> secondly, many people said that they saw man-like creatures get out of the UFOs

4.Moreover/they/talk/mysterious circles/land

=> moreover, they talk about mysterious circles on the land

5.Therefore/ There/might/existence/UFOs

=> therefore, there might be the existence ( sự tồn tại ) of the UFOs

1 i believe UFO are existed because article reports talk lots about their appearance 
2.firstly there are plenty photos of them.
3.secondly, many people said that they saw man-like creatures get out of the UFOs

4.moreover, they talk about mysterious circles on the land

5.therefore, there might be the existence of the UFOs