某生物个体减数分裂产生的配子种类及其比例为Ab∶aB∶AB∶ab=1∶2∶3∶4,若该生物进行自交,则其后代出现纯合子的概率为( )
A:30%
B:26%
C:36%
D:35%
——I can hardly believe my eyes. Is that you, Lucy?——Yes. It has been almost 20 years______ we were together.
岩石圈是指 ( )