基因YyRr的个体与YYRr的个体杂交，按自由组合规律遗传，子代的基因型有 [ ]
A．2种
B．4种
C．6种
D．8种
答案：C
The owner of the shop asked his assistant to ____ the pears that can be thrown away.
A．work out
B．make out
C．sort out
D．figure out
