A:大于25.3%
C:等于25.3%
B:小于25.3%
D:约等于25.3%
细菌与动植物细胞的结构相比,最主要的区别是( )
Fresh food is good for you. But you have to it first because sometimes it is a little dirty.
如图是一个陆地生态系统食物网的结构模式图,下列叙述不正确的是( )
我国实行计划生育政策,但目前每年新增人口仍达1200多万,主要原因是( )