Because I do not know the context of what is "cool," I am going to assume that is referring to the weather/temperature.
In Spanish, we use the verb "hacer" in expressions that refer to weather conditions.
The direct translation of "It is cool," is:
Hace fresco.
We use the third singular form of the verb hacer because we are talking about the weather.
Answer:
1.Marcos está(estar) en Yucatán
² yo soy(ser) estudiante
3 ustedes están(estar)en Argentina
4 tu estas(estar) cansada
5 nosotros somos(ser) norteamericanos
⁶. la carne está (estar) fría
7. mi abuelo es viejo
8. el gato es perezoso
9. el gato está triste
Explanation:
de nada, ya es la segunda
1.) dijo, dice 2.) dices, dijiste 3.) dijimos, decimos