依据基因重组概念的发展，判断下列图示过程中没有发生基因重组的是[ ]
A．
B．
C．
D．
答案：A
Betty shows great interest in this poem now, but she thought it boring she read it.
A．at the first time
B．the first time
C．for the first time
D．at first
经验权数法的优点与缺点？
