i am trying to fetch the data from Account object with the help of dynamic query i am getting "unexpected token: <EOF> An unexpected error has occurred. Your development organization has been notified."

because you are reffering this field also in Page.

public class SOQL3_1 {
    public List<Account> accounts{set;get;}
    public SOQL3_1(){
        List<String> listField=new List<String>{'Name','Phone','Rating','industry'};
        String queryString='SELECT Id';
        for(String s:listField){
            queryString=queryString+','+s;
        }
        queryString=queryString+' from Account';
        system.debug('queryString--> ' + queryString );
        accounts=Database.query(queryString); 
    }
}