为什么剪接是一个精确的过程
参考答案：不正确的剪接将破坏基因的编码序列。
— Do you still remember when we went to Nanjing?
— I can't remember now but ________sometime last summer?
A．might it be
B．could it be
C．could it have been
D．should it have been
按照( )方针，加快发展证券业。
A．法制
B．监管
C．自律
D．规范
E．公平
