A:3
B:4 2
C:6﹣ 2
D:2 2
——Would you like tea or coffee?——________ ,thanks. It's hard for me to fall asleep at night after drinking them.
某男子将X染色体上的某一突变基因传给儿子的概率是( )
下列都属于单细胞生物的是( )