(1)Without your help,I would not have passed the examination.       (含蓄虚拟条件句，对过去虚拟）      

=If you had not given me your help, I would not have passed the examination.                                              

没有你的帮助，我不可能通过这次考试。

(2)Without your help,I would not pass the examination. 

=If you failed to give me your help, I would not pass the examination   （含蓄虚拟条件句，对现在和将来虚拟）                                                        

没有你的帮助，我不可能通过这次考试。

(3)Without your help,I will not pass the examination. 

=If you don't give me  your help, I will not pass the examination.   （条件陈述语气）                                                       

没有你的帮助，我不可能通过这次考试。

(4)Without your help,I can not pass the examination.       （条件陈述语气）                                         

=If you don't give me your help, I can not pass the examination.          

没有你的帮助，我不可能通过这次考试。

 It is strongly suggested that Teacher Cao should not prepare four answers which are considered to be right for one choice question at a time. Hopefully Teacher Cao can take this matter into great consideration. Thanks for your great cooperation!

C,这是含蓄的条件句。时态要退一步说……