A guess: I think it might rain.
An indicator: A man comes into my house and he is all wet!
Definitive evidence: I walk out the door and get soaked. No one is spraying me with a hose. I look up and see that torrents of water is coming from the sky.
Conclusion: It IS raining.
You cannot. There is no reliable and definitive evidence that ghosts exist.
No, nor is there any definitive evidence that ghosts exist.
There is no definitive evidence that there will be such a shortage
Highly doubtful but not impossible however we have no definitive evidence
Because there is no definitive evidence that such things as ghosts exist.
So far we do not have definitive evidence that there was life on Mars. However a piece of Mars that fell to Earth as a meteorite was found to contain structures that some people interpreted as fossil bacteria. This interpretation has not been accepted as definitive.
Yes. A quick You-Tube search will yield definitive video evidence.
There is no definitive evidence that Bigfoot exists. It certainly cannot be known what its enemies are.
No. There is no definitive evidence that ghosts exist, though many people believe they do.
As there is no definitive evidence that the Loch Ness Monster is real, estimates of its age are as speculative as it existence.
The photoelectric effect was pretty definitive evidence that light is a particle (well, at least sometimes a particle).
Evidence of SID is a dead infant from no apparent cause. There are, at present, several competing theories as to why it may happen. None of them definitive. Research is ongoing.