— Mum, I've got a chance to be an exchange student to the UK next year!
— Really? That's just ________ to be true. Anyway, congratulations, baby!
A：good enough
B：well enough
C：too good
D：too well
根据课文《燕子》内容填空
遗传因子组合为RrYy的水稻自交，其子代中的性状表现、遗传因子组合形式分别是（ ）
