Помогите пожалуйста решить 3 и 4 упражнение. Заранее спасибо за помощь!

3.I am (am not) hungry.It is (is not) warm today.i am (am not) afraid of dogs.My hands are (aren't) cold.Canada isn't a very big country.Diamonds aren't cheap.I am (am not) interested in football.Rome isn't in Spain.4. Is your job interesting?Are the shops open today?Are you interested in sport?Is the post office near here?Are your children at school?