_____ from lightweight materials, the robots are about the size of a human arm or smaller.A. To build B. Being built C. Having built D. Built 答案:D
下列关于细胞增殖、分化、衰老、调亡和癌变的叙述中不确切的是
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A.细胞的衰老一定导致机体的衰老
B.细胞分裂次数受遗传物质的控制
C.细胞分化是指不同细胞遗传信息执行情况不同
D.细胞不能正常分化将会产生癌细胞