Eu diria que o 18 não está correto.

 18. The wind is strong.
O vento ESTÁ forte.

This is a hard thing to get for most people who speak English and that are trying to learn Portuguese or Spanish.
The  Verb "to be" can be translated as "SER"(mostly a quality, a stable attribute of something or of somebody) and "ESTAR" ( a state, a transitional attribute).

 For example:
O homem É alto.(SER, defining attribute, stable concept) (=The man is tall, it is not like he is going to be short the next day.)

O vento ESTÁ forte.(ESTAR, state, unstable concept) (=The wind is strong - it is blowing hard right now -, but it can suddenly lose its power, and become a weak/mild wind or a breeze). (*)

 Sometimes it can be used in both ways:
 João é gordo.(=John is fat, I'm referring his excess weight as an attribute, a defining characteristic. John has always been fat and everyone remembers and knows him as a fat man.)
João está gordo. (=John is fat. I'm referring his excess weight as a state, something that has happened recently. Everyone knows John as a fit man who has recently gained weight. Example of context would be like: After a year, I finally managed to get together with my buddy John. And I can say this: the man is fat. He must have gained at least 40 pounds. )

(*) There is no grammatical error in "O vento é forte" but this sentence expresses something in particular and therefore unusual. The wind is strong. It has, as a force of nature, the power to be strong sometimes.)