Countable vs uncountable nouns

I must use the following bolded nouns as countable nouns:

I have great memories of my grandmother, she was a very inspiring person.

She has got various abilities, that’s why she got the job.

When you are part of an Erasmus programme, you get to know a lot about other cultures.

I’m especially fond of arts related to body expression like dancing or acting.

My uncle owns businesses all over the town.

My grandmother has a farm with cows, horses and chickens.

She died because of a heart disease.

I don’t want to do these exercises because they are too difficult!

I am very nervous because of the speech I must give in front of the whole school.

I must use the following bolded nouns as uncountable nouns:

Art is a way to express our freedom.

I have some business to do with the director related to the upcoming meeting.

Chicken meat is considered to be one of the healthiest meats.

Doing some regular exercise is good for our health.

I can’t figure out how I should use “disease” and “speech” as uncountable nouns.

Thank you for your time and effort.