可阻断肠道胆固醇的吸收及激活肝脏中7α羟化酶的降脂药物是（） A.辛伐他汀 B.环丙

如图所示，要使灯L₁、L₂串联应闭合开关________，要使L₁、L₂并联应闭合开关________，为了保护电路，不能同时闭合开关_________。

联邦制为什么能够取代邦联制在美国建立？

我国四大高原各有特色，请你找出下列描述中错误的一个（　　）

A．青藏高原雪山连绵

B．内蒙古高原沟壑纵横

C．黄土高原黄土深厚

D．云贵高原地面崎岖

Part 1

Questions 1-8

·Read the article below.
·Choose the best sentence from the list on the next page to fill each of the gaps.
·For each gap (1-8) mark one letter (A-H) on the Answer Sheet.
·Do not mark any letter twice.
Poll: Obama Seen As More Compassionate Than McCain
Just hours before the start of the second presidential debate, a new national survey suggests that Sen. Barack Obama is making gains among Americans as a compassionate candidate. (1)
In a new CNN/Opinion Research Corporation poll out Tuesday afternoon, 55 percent of registered voters questioned say that Obama "cares more about people like you" than Sen. John McCain, with 35 percent saying McCain cares more than Obam

• a. (2)
  "The all-time champion of town-hall debates was Bill Clinton because he was able to connect with the audience members so well," said CNN polling director Keating Holland. "Voters nationwide seem to feel some connection with Obama. (3) John McCain has a pretty good track record at town halls, and it’s possible that he will be the one who looks more compassionate."
  Obama also appears to be building a lead as the candidate with the clearer plan to solve the country’s problems. He has a 15-point lead over McCain on that question in the poll, 48 percent to 33 percent. (4)
  Obama is also making gains on being a p and decisive leader. A 19-point McCain advantage early last month has now shrunk to a 5-point lead. (5)
  "Voters agree with McCain that things are going well for the U.S. in lraq. That’s a switch since April, when we last asked that question," Holland said. (6)
  Among voters, Obama also leads on who would better handle the economy, 57 percent to 37 percent; a financial crisis, 53 percent to 36 percent; and health care, 60 percent to 33 percent. (7)
  Obama’s favorable rating among those questioned in the poll is 62 percent, down one percentage point from three weeks ago. (8) A. But on the question of who has the better experience to be president, McCain still has a big lead over his rival, 54 percent to 36 percent.B. That could be important in the debate in Nashville, which is a town hall-style meeting with the candidates fielding questions from undecided voters in the audience.C. The question is whether he’ll connect with the people at the debate tonight.D. That 20-point margin for Obama is up from a 9-point advantage a month ago.E. McCain’s favorable rating is 54 percent, down three points from three weeks ago.F. "But voters also agree with Obama that the war was a bad idea—and they haven’t changed their minds on that in almost four years."G. McCain leads on the issue of terrorism, 54 percent to 44 percent.H. Last month, McCain had a 2-point advantage over Obama on the topic of having a clearer plan.

(12分)“速力菲”是一种人工合成的补铁剂，某研究性学习小组为探究其主要成分，进行了如下实验：

(1)打开这种药片的密封膜，发现其外观为淡黄色。

(2)将“速力菲”投入小试管中，加入少量蒸馏水，充分振荡后发现溶液变浑浊；慢慢加入稀硫酸后溶液变得澄清透明并显黄色；滴加KSCN溶液，立即变为血红色。学生甲由此断定“速力菲”的主要成分是三价铁盐。

(3)学生乙的操作与甲大致相同，所不同的是他动作敏捷，且在振荡前用橡皮塞塞紧试管口。结果发现：溶液仅显示淡红色。乙同学认为“速力菲”的主要成分不是三价铁盐而是亚铁盐。

(4)为了确认甲、乙的结论是否正确，学生丙将乙所得的淡红色溶液分成两份继续进行实验：

试完成下列问题：

(1)甲、乙两位同学的结论中比较正确的是________，另一同学的结论不合理的原因是

________________________。

(2)丙的实验①说明维生素C具有较强的________性(填“氧化”或“还原”)。

(3)写出与②中现象对应的离子反应方程式________________________________。

(4)关于③中的实验现象，丙同学提出了两种假设：一种是过量的双氧水与Fe^3＋结合生成了某种稳定的新物质；另一种则是过量的双氧水将SCN^－氧化了。请你设计一个实验方案以确认哪种假设更合理________________________________。

(5)针对实验目的，本次实验尚未完成的任务是__________________。