A:a;the
B:the;a
C:不填;the
D:the;不填
科研人员将黑色家兔胚胎细胞的细胞核移入另一只灰色家兔的去核卵细胞中,两者融合后,在体外培育成胚胎,再植入白色家兔的子宫内继续发育,所产下的小家兔的毛色应该是( )
The boy always wears ______ coat ______ his brother.