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问题 选择题

下列关于细胞分化、衰老、凋亡和癌变的叙述不确切的是[ ]

A．细胞分化一般具有不可逆性且细胞核遗传物质不会出现改变，结果是赋予不同种类的细胞特异的结构和功能

B．衰老的细胞内有些酶活性降低，癌变的细胞内呼吸速率升高

C．细胞凋亡对生物的个体发育、机体稳态的维持等有着重要作用

D．干细胞和癌细胞均属于具有正常分裂分化能力的细胞，导致发生癌变的根本原因是致癌因子使原癌基因和抑癌基因发生突变

答案

答案：D

解答题

下表是“探究馒头在口腔中的变化”的实验记录，请根据实验记录回答问题：

试管加入的物质操作水温时间试剂
①馒头碎屑+唾液充分搅拌37℃10分钟碘液
②馒头碎屑+清水充分搅拌37℃10分钟碘液
③馒头块+唾液不搅拌37℃10分钟碘液
（1）若以①和②为一组实验，则实验变量是______，其中______为对照组，加碘后所观察到的现象是：______号试管液体变蓝，______号试管液体不变色．

（2）科学探究中的数据往往存在误差，所以要设置重复组，因此就同一个实验在相同条件下要重复做几次，实验结果应取多次实验的______．
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单项选择题

Mass Protest Decries Bush Abortion Policies


群众抗议谴责布什的堕胎政策


by Deborah Zabarenko
WASHINGTON (Reuters)—Protesters crowded the National Mall on Sunday to show support for abortion rights and opposition to Bush administration policies on women’s health issues in one of the biggest demonstrations in US history.
There was no official crowd count, but organizers claimed more than 1 million people participateD．
Pink-and purple-shirted protesters raised signs reading "Fight the Radical Right", "Keep Abortion Legal" and "US Out Of My Uterus" and covered the Mall from the foot of Capitol Hill to the base of the Washington Monument.
Speakers ranged from actresses Whoopi Goldberg, Ashley Judd and Kathleen Turner to philanthropist Ted Turner, feminist icon Gloria Steinem and former Secretary of State Madeleine Albright.
Goldberg raised a wire coat hanger—a symbol of illegal abortions in the days before the Supreme Court’s 1973 Roe vs. Wade ruling recognizing abortion rights—and told the crowd, "We are one vote away from going back to this!"
She was referring to the nine-member high court, which has frequently decided abortion- related cases on a five-four vote.
The abortion issue was the centerpiece of the march’s broad protest against the policies of President Bush, including his stance on funding international family planning. No US funds may be used for any family planning agency that mentions abortion to patients.
"Vote That Smirk Out of Office," was a characteristically political placard targeting Bush, but Dorothy Smith, 76, of Eldridge, Missouri, carried an emblem she made herself—a wire coat hanger draped with a sign reading "Never Again. "
"I can remember when abortion was just as common as it is now, but it killed a lot of women," Smith saiD．
Major sponsors included stalwarts of the abortion rights movement______NARAL Pro-Choice America, Feminist Majority, National Organization for Women, Planned Parenthood Federation of America—as well as the American Civil Liberties Union, the Black Women’s Health Imperative and the National Latina Institute for Reproductive Health.
Some 1,400 groups attended the event, including an international contingent with marchers from 57 countries. There were medical students who carried signs saying they planned to be the next generation of abortion providers, and there was a Texas group marching behind a banner that read, "Old Broads for Choice. "
As the march wound from the Mall toward the White House and then turned onto Pennsylvania Avenue and toward Capitol Hill, abortion rights groups encountered antiabortion protesters.
These protesters carried posters showing photographs of fetuses at eight weeks gestation and signs reading "Abortion kills Babies. "
March organizers claimed double the turnout of the last big abortion rights march in 1992, which drew 500,000, according to the US Park Police, who no longer gives official crowd counts. The biggest demonstration was an anti-Vietnam War rally in 1969, which drew 600,000. The largest gathering on the National Mall was the 1976 US bicentennial celebration.
Though the march was billed as nonpartisan and included a contingent called Republicans for Choice, much of the day’s rhetoric was plainly aimed at Bush, a Republican who opposes abortion in most cases.
Democratic presidential candidate John Kerry vowed on Friday to champion abortion rights if electeD．He received the endorsement of Planned Parenthood’s Action Fund, the organization’s political fund-raising ann.
Neither Bush nor Kerry attended the march, but US Sen. Hillary Rodham Cfinton, a New York Democrat and former first lady, drew roars of approval when she exhorted the crowd to register to vote. Volunteers were on hand to register new voters.
Bush addressed an anti-abortion march in January, saying the effort to overturn the Supreme Court’s 1973 Roe v. Wade ruling, which recognized a right to abortion, was "noble cause. \

Which of the following is true according to the passage

A．Government officials estimated that more than one million people participated in the demonstration.
B．The police counted the number of people who participated in the demonstration as more than one million.
C．The organizers called on more than one million people to participate in the demonstration.
D．According to the organizers of the demonstration, there were more than one million people who took part in the demonstration.
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