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问题 选择题

某生物精原细胞的染色体上有2n个基因，DNA含量为6.4C（单位）。则该生物肝细胞有丝分裂后期染色体上含有的基因数和DNA含量为 [ ]

A．n和3.2C

B．2n 和6.4

C．2n和3.2C

D．4n和12.8C

答案

答案：D

单项选择题

对生活垃圾卫生填埋场垃圾渗滤液排放正确的说法是（）。

A、不得排入GB3838—2002中规定的Ⅰ、Ⅱ类水域

B、对排入GB3838—2002中规定的Ⅲ类水域的饮用水源保护区排放限制执行一级标准

C、对排入GB3838—2002中规定的Ⅴ、Ⅵ类水域排放限制执行一级标准

D、对排入GB3838—2002中规定的Ⅲ类水域排放限制执行二级标准
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填空题

President Bush arrived in Washington and forged ahead with an ambitious agenda- (1) tax cuts, vast changes in federal social programs, expansions of executive power and (2) broad remaking of energy and education policies.
Claiming a mandate by simply declaring (3) existence, his early successes dazzled his critics. With guru Karl Rove directing the (4) , Bush won a stunning series of political victories.
He muscled his agenda through (5) friendly Congress, and gained seats for his party in the 2002 midterm elections. (6) biggest triumph came in 2004, when he won a second term despite a (7) unpopular war.
The "permanent" Republican majority he and Rove envisioned even seemed attainable (8) Bush plunged himself into his most ambitious legislative effort yet: a partial privatization (9) Social Security.
But the president who boasted about "political capital" in the heady (10) after his re-election now faces the worst of political fates as he enters (11) final year in office: borderline irrelevance.
The president’s second term has (12) defined by legislative paralysis, marked by record-low approval ratings, presidential candidates who are (13) from his shadow, and a lingering war that’s sapping his remaining reservoirs of (14) .
As he enters his final year in office with the war continuing, Republican (15) for president bolting from his shadow, and his party back in the minority (16) Congress, he is politically weakened, an early entry into lame-duck status.
And the (17) Washington atmosphere he hoped to cure is just as nasty as it was (18) he came to office seven years ago.
"lie’s left our political institutions much (19) troubled than they were before," said Thomas E. Mann, a senior fellow at (20) Brookings Institution, a Washington-based think tank. "He didn’t create the ideological polarization, but he magnified it. \
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