英语中I don't think 怎么回答

Question

英语中I don't think 怎么回答
肯定回答和否定回答都要

Answer 1

yes, i think so
no, i don't think so

Answer 2

yes ,I do
no,I don't
按正常回答就行

Answer 3

So do I

Answer 4

判断think
if(think为真){
"Yes.";
}else if (think为假){
"No.";
}