They never saw it.
注：saw有“鋸”的意思，也可以理解成see的過去式，seeing is believing（眼見為實(shí)）。
更多英語(yǔ)謎語(yǔ)
Why does time fly?
What can you tell from Peter's record card with extremely poor grades?
What time is it when a man is chased by ten dogs?
What's even harder to catch if you run faster?