“张小泉菜刀”有“削铁如泥”之美称,从物理学的角度分析,这说明刀具材料的比铁大;

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问题:

“张小泉菜刀”有“削铁如泥”之美称,从物理学的角度分析,这说明刀具材料的     比铁大;刀具的刀口磨得很锋利,主要是为了增大     

考点:压强的定义
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补全对话。

A: Jack, has your brother begun school yet?

B: Yeah, he just started school last week.

A: Well, he is unhappy.

B: 1. _____________________________?

A: You see. Today school is very hard. Students are busy with their homework.

B: Yes, you are right. Schoolwork was really easy when we were six. 2. _______________?

A: Yes, we didn't worry about tests. But now I am terrified of tests.

B: Me, too. And we used to play games after school every day. Now we just study all the time.

A: Yeah, you are quite right. I'm afraid of learning English. What about you?

B: 3. ___________________, but now I am good at it.

A: Really? 4. __________________________?

B: By practicing it. It helps me a lot. Why not have a try?

A: That sounds good. 5. ________________!

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(14分)实验室中,用如下图所示装置及所给药品(图中部分夹持仪器已略去)探究工业制硫酸接触室中的反应,并测定此条件下二氧化硫的转化率。已知SO3熔点为16.8℃,假设气体进入装置时分别被完全吸收,且忽略装置内空气中的CO2

(1)已知0.5molSO2被O2氧化成气态SO3,放出49.15 kJ热量,反应的热化学方程式为                                                          

(2)根据实验目的,请从上面右图中选择Ⅰ、Ⅱ、Ⅲ处合适的装置,将其序号填入空格中:装置Ⅰ          ,装置Ⅱ          ,装置Ⅲ          

(3)开始进行实验时,首先应进行的操作是                             

(4)加热硬质玻璃管时,若不断升高温度,SO2的转化率会           (填“增大”、“不变”或“减小”)。

(5)停止通入SO2,熄灭酒精灯后,为使残留在装置中的SO2、SO3被充分吸收,操作方法是                                                           

(6)实验结束后,若装置Ⅱ增加的质量为b g ,装置Ⅲ增加的质量为a g,则此条件下二氧化硫的转化率是                 (用含字母的代数表示)。

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教师的教学方式各有特点,如果你对某一教师的教学方式不太喜欢,你应该[ ]

A.从此以后拒绝再听,以示抗议

B.找老师交换意见,请他进行指导

C.勉强听着,反正能听多少是多少

D.抓住这个时机与老师唱对台戏

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以下关于影响金价因素正确的有()

A、当全球证券市场出于牛市时,资金容易流出黄金市场,导致金价下跌

B、在一定条件下,金价与美元呈负相关

C、经济繁荣期,黄金需求量增加,刺激金价上涨

D、经济萧条期,金融形势恶化,导致金价下跌

题型:填空题

线路的有功损耗与线路的()成正比。

A、电压

B、电流

C、电阻

D、频率

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