—Tom, it’s time that you _______your own clothes.

—I would rather you _______that for me just like before.

A．washed; had done

B．wash; have done

C．washed; have done

D．wash; had washed

香味性状是优质水稻品种的重要特性之一。

单倍体育种可缩短育种年限。离体培养的花粉经脱分化形成（），最终发育成单倍体植株，这表明花粉具有发育成完整植株所需的（）。若要获得二倍体植株，应在（）时期用秋水仙素进行诱导处理。