34． What's the meaning of "UFO”？（改为同义句）

What________ ________ ________ ________ “UF0”？

Ⅵ．书面表达。（15分）

43． The cake________ (smell) good．I can-t wait to eat it．

44． Listen! There must be someone_______ (knock) at the door．

 45． The house________ (belong) to my grandfather．

42． That spy attempted________ (destroy) all the factories． Fortunately，workers found him．

41． He is going to make an________ _(appoint) with his girlfriend tonight．

39． The painting has now been returned to its rightful________  (own)．

40． The mother is________ (extreme) angry with her son when she hears that he didn-t passthe exam．

38． Doctors are．________ (worry) about the possible spread of the disease．

V．用所给词的适当形式填空。(10分)

36． This is________ (possible) their worst performance ever．