题干

下列关于细胞分化、衰老、凋亡和癌变的叙述,正确的是(  )

①个体发育过程中细胞的衰老对生物体都是有害的②正常细胞癌变后在体外培养可无限增殖③由造血干细胞分化成红细胞的过程是不可逆的④癌细胞容易在体内转移,与其细胞膜上糖蛋白等物质减少有关⑤人胚胎发育过程中尾的消失是细胞坏死的结果⑥原癌基因和抑癌基因的变异是细胞癌变的内因 ⑦低温引起的细胞冻伤和死亡属于细胞凋亡.

A:1项

B:2项

C:3项

D:4项

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D

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    Your glasses may someday replace your smartphone, and some New Yorkers are ready for the switch. Some in the city can't wait to try them on and use the maps and GPS that the futuristic eyewear is likely to include.

    “ I'd use it if I were hanging out with friends at 3 a. m. and going to the bar and wanted to see what was open,” said Walter Choo, 40, of Fort Greene.

    The smartphone-like glasses will likely come out this year and cost between $250 and $600, the Times said, possibly including a variation of augmented(增强的) reality, a technology already available on smartphones and tablets (平板电脑) that overlays information onto the screen about one's surroundings. So, for example, if you were walking down a street, indicators would____showing you the nearest coffee shop or directions could be plotted out and come into view right on the sidewalk in front of you.

    "As far as a mainstream consumer product, this just isn't something anybody needs,” said Sam Biddle, who writes for Gizmodo.com.  “ We're accustomed to having one thing in our pocket to do all these things,” he added, “and the average consumer isn't gonna be able to afford another device (装置) that's hundreds and hundreds of dollars.”9to5Google publisher Seth Weintraub, who has been reporting on the smartphone-like glasses since late last year, said he is confident that this type of wearable device will eventually be as common as smartphones.

    “It's just like smartphones 10 years ago,” Weintraub said. “A few people started getting emails on their phones, and people thought that was crazy. Same kind of thing. We see people bending their heads to look at their smartphones, and it's unnatural,” he said. “ There's gonna be improvements to that, and this a step there.”