大多数细胞产生和维持静息电位的主要原因是 （　　）

【名词&注释】

通透性(permeability)、细胞内(intracellular)、良性肿瘤(benign tumor)、印第安(indian)、大多数(most)、毁灭性的(fatal)

[单选题]大多数^(most)细胞产生和维持静息电位的主要原因是 （　　）

A. 细胞内高K+浓度和安静时膜主要对K+有通透性
B. 细胞内高K+浓度和安静时膜主要对Na+有通透性
C. 细胞外高Na+浓度和安静时膜主要对K+有通透性
D. 细胞内高Na+浓度和安静时膜主要对Na+有通透性
E. 细胞外高K+浓度和安静时膜主要对K+有通透性

查看答案&解析 查看所有试题

学习资料：

[单选题]回答{TSE}题Never laugh at a snow covered mountain! Laughter and yelling, during the avalanche season, can cause a deadly pile of snow．Huge snow slides are most common in mountains where there are steep slopes that are well buried in snow and ice．The snow builds up slowly and lands very softly．This can create a very touchy, unstable situation．Tons of snow may be held up by only the friction between snowflakes．The deep snow is like a house of cards．The slightest movement can cause it to fall．As soon as something slips, this great mass of snow will come crashing down the mountainside．Slides may be started by sound vibrations．They may also be started by the weight of wet, melting snow．Once an avalanche has been triggered, the cause no longer matters．Moving down a steep slope, it picks up great speed and added snow．Some avalanches travel as fast as two hundred miles per hour．The force of an avalanche will mow down anything in its path．Whole houses have been swallowed up by these fast-paced piles of snow．The wind that is caused by an avalanche is almost as destructive as the snow itself．Winds from an avalanche have been known to travel as fast as those of a tornado．So, when approaching a thickly snow covered mountain, speak softly!{TS}Avalanches can be started by________

A. falling snow
B. the wind
C. loud sounds
D. friction between snowflakes

[单选题]We can conclude from this passage that avalanches________

回答下面的题目Never laugh at a snow covered mountain! Laughter and yelling, during the avalanche season, can cause a deadly pile of snow．Huge snow slides are most common in mountains where there are steep slopes that are well buried in snow and ice．The snow builds up slowly and lands very softly．This can create a very touchy, unstable situation．Tons of snow may be held up by only the friction between snowflakes．The deep snow is like a house of cards．The slightest movement can cause it to fall．As soon as something slips, this great mass of snow will come crashing down the mountainside．Slides may be started by sound vibrations．They may also be started by the weight of wet, melting snow．Once an avalanche has been triggered, the cause no longer matters．Moving down a steep slope, it picks up great speed and added snow．Some avalanches travel as fast as two hundred miles per hour．The force of an avalanche will mow down anything in its path．Whole houses have been swallowed up by these fast-paced piles of snow．The wind that is caused by an avalanche is almost as destructive as the snow itself．Winds from an avalanche have been known to travel as fast as those of a tornado．So, when approaching a thickly snow covered mountain, speak softly!Avalanches can be started by________

A. are common everywhere
B. are not very common
C. have killed people
D. are a thing of the past

[单选题]_________

根据以下内容，回答下面的题目。Insure means to protect _51_ a loss of money．Most people can budget their money so that their income will cover expected expenses _52_ food, clothing, housing, and public services．But, there is no way to know _53_ who will suffer a crisis (危机) such as a serious illness, fire, flood, or a car accident．Such crises usually _54_ great expense．Even if people could predict crises, it would be hard to save enough money to _55_ the expenses．Insurance is a system _56_ a company collects money from many individuals and then pays certain expenses whenever one of those insured individuals is faced with a certain crisis．An insurance policy _57_ how much the insurance costs and how much the company will pay when a policy holder is faced with a certain crisis．There are many different kinds of insurance, _58_ hospital, motor-car and fire．Insurance can be rather expensive but most people buy insurance of some kinD．Insurance is something _59_ people buy and hope they will _60_ need．_________

A. result from
B. make
C. take
D. result in

[单选题]“Would you be_________do it for me，please?”“Of course，with pleasure．”

A. kind enough
B. as kind to
C. SO kind as to
D. so kind to

[单选题]Sequoyah was a young Cherokee Indian．son of a white trader and an Indian Squaw(北美印第安女人)．At an early age，he became fascinated by“tile talking leaf”，an expression thathe used to describe the white man’s written records．Although many believe this"talking leaf”to be a gift from tile Great Spirit，Sequoyah refused to accept that theory．Like other Indians oftile period，he was illiterate，but his determination to remedy tile situation led to the inventionof a unique 86 character alphabet based on the sound patterns that he heard． 　　His family and friends thought him mad，but while recuperating(恢复)from a huntingaccident．he diligently and independently set out to create a form of communication for his ownpeople as well as for other Indians．In l821，after twelve years of work，he had successfully de。veloped a written language that would enable thousands of Indians to read and write． 　　Sequoyah’s desire to preserve words and events for later generation has caused him to be remembered among the important inventors．The giant redwood trees of-California，called“se-quoias(红杉)”in his honor，will further imprint his name in history． 根据以上内容，回答{TSE}题。{TS}What is the most important reason that Sequoyah wiU be remeIll]bered?

A. He was illiterate．
B. California redwoods were named in his honor．
C. He recovered from his madness and helped mankind．
D. He created a unique alphabet．

[单选题]EverythingDepends on__________we get a raise in our salary．

A. what
B. that
C. if
D. whether

[单选题]How will the government know what the air quality is?

根据下列短文，回答下面的题目。　　A panel of government officials is worried．The air quality in some areas is not good．Theair is polluted with soot．The officials worry that the air is harmful to the people who breathethe air．The officials are expels．They study the environment．They diSCUSS ways to stop theair pollution．The panel decided to make，some changes to the law．　　The mew plan places strict limits on how much soot call be released into the air．Now，ameasurement of 65 parts of soot is considered safe．The new plan would reduce that number to30．The daily limit of pollution in the air would be cut in half．　　These new standards would affect industry．The limits would also affect people who ownwood stoves and fireplaces．The country will keep track of the air quality every day．Peoplewould be required to stop burning wood when the levels are high．They could also install a kindof special fireplace．These fireplaces burn very little wood．They do not pollute the air asmuch．Some countries will punish families who violate the ban．They will have to pay a fine fornot complying with the law．　　Some states do not have much industry．Their pollution problem is not too bad．Theywould stiU have to regulate how much pollution is released into the air．The experts hope thatthis ban will help keep the air cleaner．Before the plan becomes a law the public will have a chance to comment on it．Citizenswill have ninety days to ask questions and voice concerns about the plan．Then it will becomea law．The panel is made up of________．

A. The factories will test the air every day．
B. Scientists will test it every day．
C. A report will be publised．
D. They will ask homeowners．

[多选题]下列关于良性肿瘤特点的叙述，正确的是（　　）

A. 呈膨胀性扩展
B. 肿瘤边界清楚
C. 细胞形态变异较小
D. 不危及生命
E. 晚期可发生转移

本文链接：https://www.51bdks.net/show/zx5nz5.html