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:
Punctuation I believe
(Possibly none of the above because I’m not sure what they mean by punctuation)
Explanation:
A nosotros (nos gusta) mirar la televisión en casa
Yo tengo un Hermano
Hope this helps