Select the most more appropriate option to fill in the blank.

There is no need of any proof because everything is very _____.

obvious

The most appropriate option to fill in the blank is obvious.

The sentence "There is no need of any proof because everything is very obvious" means that everything is so clear and plain to see that there is no need to provide any evidence or proof. The word "obvious" is the most appropriate word to use in the blank because it accurately reflects the fact that everything is so clear and plain to see.

The other options are not as appropriate.

• The word "uncertain" is used to talk about things that are not known or not sure. This does not make sense in the context of the sentence, as the speaker is saying that everything is very clear and plain to see.
• The word "regular" is used to talk about things that happen in a fixed pattern or order. This does not make sense in the context of the sentence, as the speaker is not talking about things that happen in a fixed pattern or order, but about things that are clear and plain to see.
• The word "definite" is used to talk about things that are certain or not open to doubt. This does not make sense in the context of the sentence, as the speaker is not saying that everything is certain, but that it is obvious.