视神经萎缩症是一种显性遗传病，若一对夫妇均为杂合子，生正常孩子的概率为：
A：25%
B：12．5%
C：75%
D：45%
—Does your friend like salad?
—_________.
-- What beautiful shoes you're wearing! They must be expensive.
-- No, they only 10 yuan.
