--- Did you have anyone repair the watch?    

--- Yes. I had the watch ______ yesterday.

A．repair

B．repairing

C．to be repaired

D．repaired

在非干旱条件下选择产量潜力，不一定会产生在干旱条件下同样增产的基因型，因此可以同时选择产量潜力和对不同环境的稳定性。