If you're referring to the one who quote that sentence, it would be unknown, but it is a really famous quote.
If
you wanted to restates the main idea of this quotation , it would be :
it's not good to criticize others because we don't know that they face
in life.
hope this helps!
The purpose of this passage is to clarify what a UFO is. The passage tells you that even though UFOs often star in science fiction movies, most UFOs are actually aircraft, kites, clouds, meteors or rocket debris. It also cites a famous case in order to provide evidence for their claim.
The question is fully finished? If not then I cant help out with out the answers and the rest of the question Dx
Answer:
D. am .. is.. are, was, were