下列公式中哪一个能用来精确地计算任意浓度[c(HCl)]的HCl水溶液中氢离子浓

题型:选择题

问题:

下列公式中哪一个能用来精确地计算任意浓度[c(HCl)]的HCl水溶液中氢离子浓度

[c(H+)](Kw为水的离子积常数)                                                                        (   )                                           

A.c(H+)="c(HCl)"

B.c(H+)=c(HCl)+Kw/c(H+)

C.c(H+)=c(HCl)+Kw

D.c(H+)=c(HCl)−Kw/c(H+)

考点:弱电解质电离的影响因素弱电解质的电离度弱电解质的电离
题型:选择题
已知双曲线的中心在坐标原点,焦点在x轴上,实轴长是虚轴长的3倍,且过点(3
2
,1)
,求双曲线的标准方程及离心率.
题型:选择题

关于无连接的通信,下面描述中正确的是()

A.无连接的通信较适合传送大量的多媒体数据

B.由于通信双方的通信线路都是预设的,所以在通信过程中无需任何有关连接的操作

C.由于每一个分组独立地建立和释放逻辑连接,无连接的通信具有较高可靠性

D.无连接的通信协议UDP不能运行在电路交换或租用专线网络上

题型:选择题

光缆接续的内容包括光纤接续、()

A.铜导线连接

B.金属护套连接

C.加强芯连接

D.接头衰减测量

E.接头盒安装

题型:选择题

下列哪项吞咽训练方法可以提升咽喉部 ()。

A.门德尔松手法

B.声门上吞咽

C.呼吸训练

D.吞咽与空吞咽交替

E.屏气-发声运动

题型:选择题

It was a very hot day in the middle of summer, and there were no trees along the street. Mr. Read (41) his shop at half past five, and went out into the street and began walking to the bus. He was a very (42) man. The sun shone straight down the street, and in a few minutes Mr. Read (43) very hot.

A. up B. outC. round

A small boy came out of another (44) in the street and followed Mr. Read. He stayed very (45) him all the time, and he kicked Mr. Read’s (46) several times. Mr. Read looked at him angrily each time.After the fourth time, Mr. Read stopped, turned (47) and said to the small boy, "What are you doing (48) following me like that! You’re going to hurt my feet."
"I’m (49) , but don’t stop me, please!" the small boy said. "It’s very hot today, and there isn’t (50) shade anywhere else in the street!\

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