Who is sleeping at home?
A:Tom's brother.
B:Tom's father.
C:Tom's mother.
克隆技术属于____工程,克隆出的动物与提供____的动物几乎相同。如多利羊的培育,这种方式属于____繁殖。多利羊与以往的克隆动物的最大区别是:多利的细胞核来源于____,不是早期的细胞。
— does the rain come from? —It comes from the clouds.
﹣4.5×10﹣5表示( )