有关水的说法正确的是（） A．水电解时产生的两种气体的质_爱下问搜题

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问题选择题

有关水的说法正确的是（　　）

A．水电解时产生的两种气体的质量比为2：1

B．湿衣服晾干说明分子作不断运动

C．水变成水蒸气，水分子变大

D．净化水时可用明矾作消毒剂

答案

A、水通电分解时观察到产生氢气与氧气的体积比为2：1，而非质量比．故A错误；

B、湿衣服上的水扩散到空气中是由于构成水的分子不断运动的结果．故B正确；

C、水变成水蒸气是由于水分子间间隙变大而非水分子本身变大．故C错误；

D、净化水的过程中，明矾凝聚悬浮于水中的固体小颗粒而加快沉降，通过氯气才起到消毒杀菌作用．故D错误；

故选B．

完形填空

When our restaurant business failed，we headed north in a camping truck to Texas，hoping to have a “fresh start”.
At the     of Palo Duro Canyon (峡谷）State Park，I     a job advertisement hiring park hosts. The position offered a     ，permanent campsite in the park, and     , the hosts served as a link between the park’s guests and the rangers (护林人). It was the perfect solution: a rent-free place to reorganize our lives. We entered the park and I made an     for the following day.
The park was     , so it took us some time to find an available site. That evening, as we finished our dinner, my wife saw two large skunks (臭鼠由）walking toward our table. We     climbed onto the table and, for the next four hours, waited for them to     our camp.
Having survived that night, we were     that everything else would be all right. The next day we met with the people who ran the park. They explained our     and gave us a beautiful campsite.
That evening,     , we learned about the canyon    . They were strong and cold, rocking our little camping truck violently，and we lay     in the dark until the winds died away.
   the weeks that followed, we learned to survive in our truck and     the little money my wife     by substitute teaching. Building a successful business and then losing it had left very little time for building a successful     For a time after our business    I thought I might lose my family as well.
Living in the tiny     with no television, we sat close together reading and talking. One evening, standing under a jeweled sky，I found myself     for all the hardships. We had walked the trails and climbed the canyon walls. We had become a family!

B．immediately

A．responsibilities

B．requirements

C．circumstances

B．quarrelling

问答题简答题

20世纪西方文学的基本主题。