有机物X能实现下列转化,下列判断一定错误的是() A.X可以是淀粉或纤维素 B

题型:选择题

问题:

有机物X能实现下列转化,下列判断一定错误的是(  )

A.X可以是淀粉或纤维素

B.有机物Y在浓H2SO4、加热条件下一定发生消去反应

C.Y→乙醛的反应属于氧化反应

D.有机物X可能有醛基

考点:有机物的推断
题型:选择题

情景交际。

     根据对话内容,从对话后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。

Jack: Good morning!   1  

Secretary: Good morning! How can I help you?

Jack: Jack Hudson. Absolutely Arizona Mineral Waters. Here's my card.   2   

Secretary: The sales manager?

Jack: Yes, is he in?

Secretary: Mr. Alvarez is in.   3  

Jack: Uh, no, he isn't, but…

Secretary:    4   

Jack: No, I don't, but…

Secretary: Mr. Alvarez is in a meeting.

Jack: I can wait. Secretary: Sorry.   5  

A. Is he expecting you?

B. So you don't have an appointment.

C. I haven't seen you for ages.

D. Is he familiar with you?

E. Can I see the manager?

F. He has appointments all day.

G. And how are you today?

题型:选择题

袋中有红、黄、白三种颜色的球各一个,从中每次取一只,有放回的抽取三次,

求:(1)3只球颜色全相同的概率;

(2)3只球颜色不全相同的概率;

(3)3只球颜色全不相同的概率.

题型:选择题

初级生产

题型:选择题

班集体的形成经过了哪些阶段

题型:选择题

内存的指标包括()

A.存取时间

B.CAS延迟时间

C.奇偶校验

D.ECC

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