北京奥运会火炬“祥云”将于今年5月10日到达我市，它使用的燃料_爱下问搜题

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问题选择题

北京奥运会火炬“祥云”将于今年5月10日到达我市，它使用的燃料是丁烷，丁烷的化学式是C₄H₁₀，下列关于丁烷的说法中，正确的是（　　）

A．丁烷由碳和氢气组成

B．丁烷由4个碳原子和10个氢原子构成

C．丁烷中碳元素和氢元素的质量比为2：5

D．丁烷是有机化合物，完全燃烧生成水和二氧化碳

答案

A、根据丁烷的化学式是C₄H₁₀，丁烷由C、H两种元素组成，而不是由碳和氢气组成，故A不正确；

B、根据丁烷的化学式是C₄H₁₀，其分子由4个C原子和10个H原子所构成，而不是丁烷由4个碳原子和10个氢原子构成，故B不正确；

C、丁烷C₄H₁₀中碳元素和氢元素的质量比=（12×4）：（1×10）=24：5≠2：5，故C不正确；

D、有机化合物是指含C元素的化合物，根据丁烷的化学式是C₄H₁₀，丁烷由C、H两种元素组成的化合物，属于有机化合物；完全燃烧时其中H全部生成水、其中C全部生成二氧化碳；故D正确；

故选D．

完形填空

A few days ago, I was having a meeting in my company. After walking out, I 36 for my car keys in my pocket, only to discover they were not there. 37 , I gave myself a quick personal pat 38 my clothes, but they were not in 39 of my pockets. So, I went back to the meeting room and looked for them in every place _ 40_I had been. Suddenly it occurred to me that I must have left them in the car. Worried and frightened, I quickly 41 for the parking lot.（停车场）
My wife, Diane, has 42 me many times for leaving the keys in the ignition（点火处）. My theory is the ignition is the 43 place so that I won’t lose them. Her theory is that the car will be 44 . As I rushed out of my company, I came to a terrifying 45 . Her theory was right. The parking lot was 46 .
Without hesitation, I called the 47 . I gave them my location（位置）and 48 that I had left my keys in the car, and that it had been stolen. Then I made the most 49 call of all.
“Honey,” I said in a low voice. I always call her “honey” in times like these. “I 50 my keys in the car, and it has been stolen.”
There was a period of 51 . I thought the call had been dropped, but then I heard Diane’s 52 .
“Ken,” she shouted, “I dropped you off!”
Now it was my time to be silent. 53 , I said, “In that case, would you please come and 54
your dear husband?”
Diane answered, “I will... just as soon as I can have this policeman 55 I didn’t steal your car.”

B．Fortunately

B．disappointment

B．Embarrassed

单项选择题

会计核算中的会计处理方法和程序在前后各期( )。

A．可以随意改变

B．经上级主管部门批准后，即可更改

C．应当一致，不能任意变动

D．绝对不能变动