A:将细胞与外界环境分隔开
B:控制细胞的代谢和遗传
C:控制物质进出细胞
D:进行细胞间的信息交流
_________ he was very tired, he continued working in his office.
“亲子鉴定”常从血液中提取DNA,DNA主要来自于血液中的( )
手被针刺了,立刻缩回来,这种反应叫做( )