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某校兴趣小组同学为探究铁的化学性质，如图进行了以下三个实验，请回答有关问题：

（1）实验一：所发生反应的化学方程式是______，实验结束后可能产生的不良后果是______；

（2）实验二：关闭K一段时间后，观察到导管内液面上升；打开K，滴加稀盐酸，观察到导管内液面下降，导管口有气泡冒出，关闭K，导管内液面上升的原因是______；导管内液面下降的原因是______．（用化学方程式解释）．

（3）实验三：实验观察到的现象是：______，这一现象说明______（填“铁”或“铜”）的活动性更强．

答案

（1）铁在氧气中燃烧生成黑色固体四氧化三铁，反应的化学方程式为：3Fe+2O2

点燃
.
Fe3O4；集气瓶底预先铺上一层细沙或少量的水，防止生成物落下来炸裂集气瓶；

（2）铁在潮湿的空气易生锈，消耗空气中的氧气，使瓶内压强减小，所以观察到导管内液面上升；盐酸和铁反应生成氢气，所以使瓶内压强变大，观察到导管内液面下降，导管口有气泡冒出，化学方程式为Fe+2HCl=FeCl2+H2↑．故填：铁在潮湿的空气易生锈，消耗空气中的氧气，使瓶内压强减小，所以观察到导管内液面上升；Fe+2HCl=FeCl2+H2↑．

（3）铁能与硫酸铜发生置换反应生成硫酸亚铁和铜，硫酸亚铁的水溶液为浅绿色，铜为红色．故：实验三：实验观察到的现象是：有红色固体析出，蓝色溶液变浅绿色，这一现象说明 铁的活动性更强．

故答案为：（1）3Fe+2O2

点燃
.
Fe3O4；集气瓶破裂

（2）铁生锈消耗了瓶内的氧气，瓶内气压小于外界大气压，液面上升；Fe+2HCl=FeCl2+H2↑

（3）有红色固体析出，蓝色溶液变浅绿色；铁

完形填空

The Atlantic Ocean is one of the oceans that separate the Old World from the New. For centuries it kept the Americans from being discovered by the people of Europe.

It is more than 4,000 miles (6,400 km) wide where Columbus crossed it. Even at its narrowest it is about 2,000 miles (3,200 km) wide.   小题1:  .

Two things make the Atlantic Ocean rather unusual. For so large an ocean it has very few islands.   小题2: .

One of the longest mountain ranges of the world rises from the floor of the Atlantic.  小题3: . The tops of a few of the mountains reach up above the sea and make islands. The Azores are the tops of peaks in the mid-Atlantic mountain range.

Ocean currents are sometimes called “rivers in the sea”. One of these “rivers” in the Atlantic is called the Gulf Stream. It is a current（流） of warm water. Another is the Labrador Current --- cold water coming down from the Arctic.  小题4: .

Today the Atlantic is a great highway. It is not, however, always a smooth and safe one. Storms sweep across it and pile up great waves. Icebergs float down from the far north across the paths of ships.

 小题5:. Columbus sailed for more than two months to cross it. A fast modern steamship can make the trip in less than four days. Airplanes fly from New York to London in only eight hours and from South America to Africa in four!

A We now have such fast ways of traveling that this big ocean seems to have grown smaller

B This narrowest place is between the bulge（鼓起） of South America and the bulge of Africa

C Also, it is the world’s saltiest ocean

D This big Atlantic Ocean is not easy and sometimes dangerous to cross

E This mountain range runs north and south down the middle of the ocean

F Ocean currents affect the climates of the land near which they flow

G The Atlantic furnishes much food for the people on its shores
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单项选择题 共用题干题

患者女，29岁，孕39周，在硬膜外阻滞下拟行剖宫产术。平卧位试验剂量后给予2%利多卡因初量13ml，13min后出现低血压、心动过速，自述头晕等表现。

若产生误吸，支气管痉挛，下列处理不恰当的是（）

A.给予地塞米松

B.加深麻醉

C.雾化吸入双羟茶碱（喘定）

D.静脉注射氨茶碱

E.加大肌松剂剂量
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