将一代杂种再和亲本之一杂交称为（）。
A.成对杂交
B.复合杂交
C.回交
D.亲缘杂交
参考答案：C
We don’t know how to remember these English words. Can you give us ____________?
A．an advice
B．some advice
C．many advices
D．any advice
