Помогите!!!!СРОЧНО!!!!

1/ I am verry sorry, but I cant. My mom is ill.
2/ I am not sure.
3/ sure
4/ I am not sure. или Iam not sure about the answer или I have no answer.

1) Sorry, I can`t. My mom is sick.
2) But I`m not sure
3) I`m pretty sure 
4) To be honest, I don`t...