相信你认识了不少生物,也学会了区分生物和非生物,下列属于生物的是( )
A:孔子鸟化石
B:珊瑚
C:钟乳石
D:石头上的青苔
He was ____ (homeless/homelessness), so we took him in.
I'm very happy to ____ my friend in Australia.(hear)
下列关于植物体细胞杂交的叙述,错误的是