否定之否定规律是唯物辩证法的实质和核心。（）

A、爆炸极限越宽，爆炸下限越低，爆炸危险性越小
B、爆炸极限越宽，爆炸上限越高，爆炸危险性越小
C、爆炸极限越宽，爆炸下限越低，爆炸危险性越大
D、爆炸危险性与爆炸极限无关

A．Egg stays in the tubal ampullary waiting for fertilization
B．The main part for sperm capacitation is the vagina
C．Acrosome reaction occurs when sperm and egg meet
D．Meeting of sperm and egg marks the beginning of fertilization process
E． Fusion of prokaryotic nucleus with ovoid nucleus marks the completion of the fertilization process