2003年3月25日22时25分，“神舟”三号飞船搭载了刚产出两天的受精乌鸡蛋进入太空，科学家想研究太空环境对鸡的（　　）的影响．

A．受精卵

B．胚胎

C．胚盘

D．卵细胞

_________for the free tickets,I would not have gone to the films so often.     [ ]

A.  If it is not                                      

B.  Were it not      

C.  Had it not been                                    

D. If they were not