选用恰当的连接词填空。 whether, that, what, as if, why, as 1. I'm wondering ____ you are always late  for class. 2. I am not sure ____ he will lend me ahand. 3. My parents are very kind to me and  always let me do ____ I think Ishould. 4. The trouble is ____ I am anxious to  telephone Mr Srmth but I have lost hisnumber. 5. He looked just ____  he had looked ten   years ago. 6. It sounds ____ someone is knocking at  the window.