问题 选择题

物质在潮湿的空气中发生的变化,主要与空气中某些气体有关.下列有关说法中不正确的是(  )

A.钢铁生锈与氧气、水蒸气有关

B.氢氧化钠固体潮解、变质,与水蒸气、二氧化碳有关

C.生石灰堆放久了变质与氧气有关

D.浓硫酸露置于空气中导致溶质质量分数减小与水蒸气有关

答案

A、铁生锈的条件是与氧气、水共同接触;说法正确;

B、氢氧化钠固体具有吸水性,易吸收空气中的水分而潮解,还能与空气中的二氧化碳反应生成碳酸钠而变质.说法正确;

C、生石灰堆放在空气中,易与空气中的水反应生成氢氧化钙,氢氧化钙还能继续与二氧化碳反应,与氧气无关,故说法错误;

D、浓硫酸具有吸水性,露置于空气中能吸收空气中的水导致溶质质量分数减小.说法正确.

故选C

选择题
阅读理解

阅读理解

      The year was 1932. Amelia Earhart was flying alone from North America to England in a small

single-engine airplane. At midnight, several hours after she had left Newfoundland, she ran into bad

weather. To make things worse, her altimeter failed.(The altimeter shows the height of the plane above

the ground.) At night and in a storm, a pilot is in great difficulty without an altimeter. At times, her plane

nearly plunged into the Atlantic Ocean.

     Just before daylight, there was further trouble. Amelia noticed flames coming from the engine. Would

she be able to reach land? There was nothing to do except to keep going and to hope.

     Amelia Earhart did reach Ireland, and for the courage she had shown, she was warmly welcomed in

England and the rest of Europe. When she returned to the United States, she was honored by President

Hoover at a special dinner in the White House. From that time on, Amelia Earhart became famous.

     What was so important about her flight? Amelia Earhart was the first woman to fly the Atlantic Ocean

alone, and she set a record of fourteen hours and fifty-six minutes.

1. Amelia's flight was important because __________.

A. Amelia was a woman pilot

B. She set a record for the flight

C. Amelia was the first woman to fly across the Atlantic alone

D. Amelia was able to overcome the difficulties during the flight

2. She ran into bad weather. Here "ran into" means __________.

A. rushed into

B. raced into

C. met into

D. met with

3. Amelia's successful flight proved that __________.

A. women can do everything

B. women can do tings that men have done

C. men and women are equal now

D. women pilots are more successful than men pilots

4. The best title for this passage would be __________.

A. Amelia Earhart

B. A Woman Pilot

C. A Flight

D. An Honoured Women