[操作要求] 使用ACE扩展对象制作花草，如图1-19A所示。 1．创建模型

对于一个化学反应的研究需要从反应条件、限度、速率、定量关系等因素进行综合分析，下列是关于化学反应的系列研究，请根据相关信息回答问题。

⑴关于反应物之间的定量关系的研究：

已知反应：Br₂ +2Fe²⁺=2 Br ^-+2Fe³⁺,向10 mL0 .1mol/L的Fe Br₂溶液中通入0 .003mol Cl₂，该反应的离子方程式为                                   

⑵关于反应速率、限度的研究：

①已知298K时，Mg(OH)₂的溶度积常数Ksp＝5.6×10^－12，在氯化镁溶液中加入一定量的烧碱，测得pH=13.0,则此温度下残留在溶液中的c(Mg ²⁺)＝               

②科学研究发现纳米级的Cu₂O可作为太阳光分解水的催化剂。

一定温度下，在2L密闭容器中加入纳米级的Cu₂O并通入0 .1mol水蒸气，发生反应：

2 H₂O(g)         

2 H₂(g) + O₂(g)△H＝+484kJ· mol^-1，不同时段产生O₂的量见下表：

时间/min	20	40	60	80
n(O2)/mol	0.0010	0.0016	0.0020	0.0020

则前20min的反应速率v(H₂O)=                 ；达到平衡时，至少需要吸收的光能为             kJ。

③向某密闭容器中加入0 .3molA、0 .1molC和一定量的B三种气体。一定条件下发生反应，各物质浓度随时间变化如下图中甲图所示。附图中乙图为t₂时刻后改变容器中条件，平衡体系中反应速率随时间变化的情况，且四个阶段都只改变一种条件。已知t₃～t₄为使用催化剂，甲图中t₀～t₁阶段c (B)未画出。请回答：

Ⅰ：t₄～t₅阶段改变的条件是         t₅～t₆阶段改变的条件是               

Ⅱ：B的起始浓度为              ，该反应方程式为                      

This year will mark the 120th birthday of the Eiffel Tower. What gift will the Paris monument get? It will be given a fresh coat of brown paint. About 60 tons of paint to be exact, in a specially mixed color called “Eiffel Tower Brown”.

The landmark (标志性建筑) gets a new coat of paint every seven years. In the past the tower has gone from reddish brown to yellow, brownish-yellow and dark red, before operators settled in 1968 on the current color.

“This is the color that suits the tower best－its most elegant （优雅的）dress,” said Jean-Bernard Bros, head of he company that operates the tower. “So we have decided to keep the brown for good.”

The Eiffel Tower is the world’s most visited tourist attraction. It was designed and named after the French architect (建筑师) Alexandre Gustave Eiffel, who was also responsible for the frame of the well-known Statue of Liberty in the US.

However, when the tower was first built, it was highly controversial (有争议的). Artists and politicians, including Maupassant (莫伯桑) and Alexandre Dumas (大仲马), spoke out against it. They described it as ugly and said its presence lowered French taste.

67. What’s the best title of the passage?

A. The Eiffel Tower.    B. Birthday gift for the Eiffel Tower

C. How to celebrate the birthday of the Eiffel Tower    D. The history of the Eiffel Tower

68. How often does the Eiffel Tower get a new coat of pain?

A. Every year.    B. Every two years.    C. Every six years.    D. Every seven years.

69. According to the passage, which of the following is WRONG about the Eiffel Towel?

A. It is a place of interest which is most visited in the world.

B. A French architect named Alexandre Gustave Eiffel designed it.

C. Some people expressed their dislike about it when it was first built.

D. The Eiffel Tower was once painted black.

70. The underlined phrase “for good” in the third paragraph means ______.

A. forever    B. temporarily    C. beneficially    D. properly

如图，不可伸长的轻质细绳跨过光滑的轻质滑轮，绳两端各系一小球．a球质量为m，静止于地面；b球质量为3m，用手托住，高度为h，此时绳刚好拉紧．从静止开始释放b，a上升的最大高度为______．（a球不会碰到滑轮）

【5】 的功能是用于显示当前过程中的有关信息，当测试一个过程时，可在其中输入代码并立即执行。

世界贸易组织现有成员148个，中国于2001年12月11日正式成为世贸组织第143位成员。( )