They are assertions which have no verifiable supporting evidence. And especially re: WTC 1993, there is virtually nothing to support the text at all.
Can you show me a source that says Osama had no connection to the 1993 WTC attack? Even one with no supporting evidence?
And you still haven't told me who could have perpetrated the attacks, and why it would be so helpful to our government to keep that person/group secret. Why would it be so important for the government to not let the truth out?