题目

The student, who gave his life to save a child, was ______ honor to our school. A memorial is held here every year in ______ honor of him. A . an; the B . an; / C . the; the D . a; / 答案：B已知Aa的个体在繁殖后代的过程中有纯合显性致死现象，则该种个体连续自交2代之后的性状分离比为（设：A控制白色，a控制黑色）A．1：2B．1：4C．1：3D．2：3