How to use IN clause in Dynamic query?

MAP<ID,Opportunity> os = new MAP<Id,Opportunity>([Select ID from Opportunity]);
SET<ID> keys = os.keyset();
String s = 'SELECT RecordTypeId, COUNT(Id) os FROM Opportunity Where Id IN ';
s+=':keys GROUP BY RecordTypeId';
AggregateResult[] ars = Database.query(s);
System.debug(ars[0].get('RecordTypeId'));

Hi

list<string> setAccIds = new list<string>();
setAccIds .addAll(AcctoCon_Sync.keySet());

AccQuery = 'SELECT Id ,AccArticleId , ' + title + ',' + answer + ' FROM ' + articleType;
AccQuery += ' WHERE PublishStatus = \'Online\' AND language = \'en_US\' AND AccQuery IN :' + setAccIds ;

Thanks