题干
After Billy said he would ride a mountain bicycle, his father _____ to him and bought him one.
A：gave away
B：gave i
C：gave u
D：gave out
答案(点此获取答案解析）
B
因。）此等位基因表达受性激素影响，TS在男性为显性，TL在女性为显性。若一对夫妇均为短食指，且丈夫为色盲患者，妻子表现正常。所生孩子既有长食指又有短食指，既有患色盲也有不患色盲。则该夫妇再生一个孩子是长食指且为色盲患者的概率为（ ）
