Hello! My name is Jack. I'm 1Changsha. I'm in No.1 Middle School. It's 2good school. My school ID card 3 is 2016701. John is 4English friend. His 5name is Brown. John is in Changsha No.5 Middle School. We(我们) can 6in the evening. Sally and Jane are John's 7sisters(妹). Sally is 10. Her favorite (最喜欢的) 8is blue. Her cup and jacket are 9. Jane is 2. She can say "10are you?" to me now.

下列关于人体神经系统组成的叙述错误的是（    ）

2009年10月5日，三位科学家因发现“端粒和端粒酶是如何保护染色体的”而获得本年度诺贝尔生理学或医学奖。端粒被一部分科学家们视为“生命时钟”，是位于染色体末端的一种特殊构造，它随着细胞分裂而变短。癌细胞中存在延长染色体端粒的酶，正常人的生殖细胞中也有。据此你认为正常体细胞不能无限分裂的原因是