问题
                    
We can’t do well in examination _________ we studyhard in school time.
                            A:if
B:and
C:since
D:unless
                        
                        B:and
C:since
D:unless
正确答案是:
                         
                        
                        
                    同类题型
                    Some people think _______about their rightsthan they do about theirresponsibilities
They don’t know that Tom Cruise is an American star _______ is famous all over the world.
Would you like to spend the vacation in Paris with me? –I’d like to______ you pay for me
ly, workshard can be they want to be, whetherit is a pilot, an engineer or a manager.
It is known to us all E-mail is______ efficient than sending a fax.