薄荷醇(化学式为C10H20O)可用于糖果、饮料的香.下列有关薄荷醇的说法正确的

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问题:

薄荷醇(化学式为C10H20O)可用于糖果、饮料的香.下列有关薄荷醇的说法正确的是(  )

A.薄荷醇不属于化合物

B.薄荷醇由10个碳原子、20个氢原子和1个氧原子构成

C.薄荷醇中碳元素、氢元素和氧元素的质量比为10:20:1

D.薄荷醇中碳元素的质量分数约为76.9%

考点:化学式的写法和意义分子的定义原子的定义物质组成元素的质量比物质组成元素的质量分数
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在探究“光对鼠妇生活的影响”活动中,用10只鼠妇而不用1只是为了                                                                       。(1分)

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It doesn’t matter when or how much a person sleeps, but everyone needs some rest to stay alive. That’s what all doctors thought, until they heard about Al Herpin. Al Herpin, it was said, never slept. Could this be true? The doctors decided to see this strange man themselves.

Al Herpin was 90 years old when the doctors came to his home in New Jersey. They thought for sure that he got some sleep of some kind. So they stayed with him and watched every movement he made. But they were surprised. Though they watched him hour after hour and day after day, they never saw Herpin sleeping. In fact, he did not even own a bed. He never needed one.

The only rest that Herpin sometimes got was sitting in a comfortable chair and reading newspapers. The doctors were puzzled by his strange continuous sleeplessness. They asked him a lot of questions, hoping to find an answer. They found only one answer that might explain this question. Herpin remembered some talk about his mother having been injured several days before he was born. But that was all. Was this the real reason? No one could be sure.

Herpin died at the age of 94.

小题1:The doctors came to Herpin’s home in order to __________.

A.treat him for his illness

B.find the reason why some old people didn’t need any sleep.

C.get some proof to show his sleeplessness was not really true.

D.help him to have a rest in some day.小题2:After watching him closely, the doctors came to believe that Al Herpin ________.

A.needed some kind of sleep.

B.needed no sleep at all.

C.was too old to need any sleep.

D.often slept in a chair.小题3:Al Herpin’s condition could be regarded as ___________.

A.an unusual one

B.a common one

C.very healthy

D.very funny小题4: The main idea of this passage is that ____________.  

A.large numbers of people do not need sleep

B.everyone needs some sleep to stay alive

C.people can live longer by trying not to sleep at all

D.a person was found who actually didn’t need any sleep

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患儿女,11岁。牙龈出血伴头晕乏力1个月,发热、咽痛2天入院。查体:T 38.9℃,颈部、腋窝及腹股沟淋巴结明显肿大,胸骨压痛,肝肋下2cm、脾肋下4cm。血常规检查:Hb 48g/L,WBC 29×109/L,PLT 76×109/L,外周血有无法分类的细胞。

患儿骨髓细胞学检查可发现哪些变化

A.骨髓有核细胞增生极度活跃或明显活跃

B.粒系和红系均受抑制

C.原始和幼稚淋巴细胞>30%

D.可见Rieder细胞和退化细胞

E.蓝细胞多见

F.巨核细胞减少

G.嗜碱性粒细胞增多

H.Ph染色体阳性

I.白血病细胞中可见Auer小体

题型:选择题

在舞会上保持良好的风度,有哪四个方面?

题型:选择题

关于视神经胶质瘤,下列描述正确的是()

A.低度恶性

B.学龄前儿童多见

C.双侧同时发病

D.一侧视神经孔扩大

E.可伴发神经纤维瘤病

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