基因的自由组合定律中，“自由组合”是指[     ]

A．等位基因的自由组合

B．不同基因的雌、雄配子间随机组合

C．亲本不同基因的组合

D．非同源染色体上非等位基因的组合

We used to work in the same office and we____ often have coffee together, which I missed so much years later.

A．would

B．should

C．could

D．might