after all, it was rumored that smoking caused cancer for years before the evidence was found to prove a connection.

what's auther's meaning?
does he means there are connections between smoking and cancer?
but why he said it was a rumor?

Question

after all, it was rumored that smoking caused cancer for years before the evidence was found to prove a connection.

what's auther's meaning?
does he means there are connections between smoking and cancer?
but why he said it was a rumor?

Answer

Before evidence was available to show that there definitely was a connection between smoking and cancer, people believed it and talked about it. If many people are discussing something that hasn't been proven you can describe that thing as a rumour.

Answer

hello
can we practice together?