Article: singular/plural of nouns

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I can distinguish this “tire” in this context becuase “tire” has different meanings. The first means a part in vehicles and second means a type of material. This is not so difficult for me. I give the following examples:

This student has technique to do experiments.
This student has techniques to do experiments.
This student has the technique to experiments.
This student has the technique to solve this problems.
This new building is full of new technique.
This new building is full of new techniques.
Today, very country realizes the importance of new technique.

Can Alan help to comment the above sentences? Which is correct and why?

This come from Alan’s web:
Before a noun made definite by the addition of a phrase or clause.
“The woman dressed in black.”

I understand that “woman” in this sentence is made definite and “woman” is a countable noun. If I want to express the concept: all women who wear black clothes. should I say " the women dressed in black" or “women dressed in black”

I want to give another example: the water in the cup. Here, “water” is made definite by “the cup”. How about this example: water in seas or water in rivers. Should I say " the water in seas or the water in rivers"? Can I say “seas” or “rivers” make “water” definite?