A:RNA病毒中没有DNA
B:酵母菌细胞中的DNA都分布在细胞核
C:真核细胞的细胞质基质存在DNA
D:原核细胞如果含RNA就不含DNA
I find difficult for Tom to reach that picture.He is a little short.
下列设备的运行与电磁波无关的是 ( )
His mother is ill at home, so he has to take care of her today.
把它们放在笼子里.
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