问题 选择题

某可燃物4.6g 在足量氧气充分燃烧,生成8.8g 二氧化碳和5.4g 水,则该可燃物的组成为:

A.一定含碳、氢、氧三种元素元素

B.一定含碳、氢元素,可能含氧元素

C.一定含碳、氢元素,不含氧元素

D.所含元素大于三种

答案

答案:A

生成的8.8g二氧化碳和5.4g水中C、H元素质量分别为:

C元素质量=二氧化碳的质量×二氧化碳中碳的质量分数=8.8g×12 /44 ×100%=2.4g;H元素质量=水的质量×水中氢的质量分数=5.4g×2/18 ×100%=0.6g;

C、H元素质量和=2.4g+0.6g=3g;

∵3g<4.6g,∴可燃物中除C、H元素外还含氧元素;

故选A

填空题

阅读下面短文,按照句子结构的语法性和上下文连贯的要求,在空格处填入一个适当的词或使用括号中词语的正确形式填空。

     There is a very famous traditional Chinese story that has a close connection to the Dragon Boat

Festival.Once upon a time on Emei Mountain there lived two __1__ spirits,White Snake and Green

Snake.These snakes,being magical,turned themselves into beautiful maidens and set off on a journey to the West Lake of Hangzhou.

     When they arrived at the West Lake they met a man __2__(name)Xu Xian.White Snake quickly fell in

love with Xu Xian and they were soon married.A Buddhist monk,named Fa Hai,warned Xu Xian __3__

his wife's deceptive(欺骗性的)appearance and suggested to him a plan.

     On the day of the Dragon Boat Festival,White Snake wished to stay home so as to avoid the Ay Tsao(艾草),used for protection from spirits,__4__(hang) on the doors of people's houses.Her husband

prepared,according to Fa Hai's __5__(instruct),some realgar wine(雄黄酒),as this was a tradition during

the Dragon Boat Festival.White Snake,thinking her magic __6__(protect)her from the effects of the realgar wine,accepted a cup.__7__ she drank the wine she became very ill and was barely able to get to her bed.

When her husband came to her side,he found not his wife but a huge white snake.So great was Xu Xian's

shock that he fell to the floor __8__.

     After recovering from the realgar wine and regaining her human form,White Snake was griefstricken to

find her husband dead.She set off on a journey to obtain a potent(有效力的)medicinal herb,__9__ could

revive her husband.After returning and reviving her husband with the medicine,she explained to Xu Xian

that the white snake he saw was __10__(actual)a dragon and that this vision was indeed a very good

omen(预兆).Xu Xian's fears were put to rest for the moment by his wife's story.

单项选择题 案例分析题