For anyone struggling with supporting claims I recommend taking a University level logic class. The definition drilled into your head follows:

"If and only if the premise(s) are true, then the conclusion must also be true."

For example:

If Opus is a penguin, then Opus is a bird.

Opus is a bird, therefore Opus must be a penguin.

The argument above is considered invalid as the premise does not sufficiently support the claim. The premise supports that Penguins are birds, but not that birds are always penguins.

An example of a sufficiently supporting argument is as follows:

If X is a penguin, then X is a bird.

Opus is a Penguin; therefore, Opus is a Bird.

The difference between the two of these arguments is that the premise of the second argument sufficiently supports the conclusion. If Opus is a Penguin then Opus is a bird, Since Opus is a Penguin, it logically follows that Opus is a bird. The first argument fails to justify the conclusion through the support of the premise.

@regggy If you are still a University Student (and your university offers it), please consider taking Logic 1! I took it last semester and a massive part of the curriculum is "Necessary and sufficient clauses."

Most buildings in downtown Houston are made of brick.

All buildings made of brick are much more structurally sound.

Therefore, most of downtown Houston is confidently structurally sound.