问题 单项选择题

影响肾排H的主要因素是()。

A.通过碳酸酐酶的作用,H与重碳酸盐结合

B.H与肾小管液中的NH,结合形成NH广

C.H结合形成H2SO4而分泌出来

D.H与Cl结合为HCl

E.H与醋酸盐结合

答案

参考答案:B

解析:

[解题思路] 分泌NH3与小管液中的H结合生成[*],H浓度降低促进H的分泌。[*]进一步与小管液中的强酸盐(如NaCl)的负离子结合,生成酸性铵盐(如NH4Cl),并随尿排出。

[命题规律] 考察“肾小管对H+的分泌”。重点掌握。

阅读理解

Do you have a sore throat, a running nose and a headache? Do you keep coughing and sneezing? If you do, the chances are that you have a cold or perhaps flu--- but which one? Although both colds and flu are caused by viruses, they are very different illnesses.

Colds, which usually last about a week, affect the nose most. They commonly cause a runny nose and sneezing. Sometimes, they cause a headache, a cough and slightly aching muscles.

Flu is much more serious illness and is caused by different group of viruses. People with flu usually get all the symptoms described above. However, they also get a high fever, a dry cough and much worse aching. Fever is one of the typical symptoms of the flu for all ages. The symptoms also last much longer. Sometimes they don’t disappear for at least two weeks.

Flu can be a deadly disease. The elderly, who are weaker and less healthy than most younger people, can die from flu. This is one reason why old people are advised to have a flu injection before the start of winter when flu is most common. This injection is inexpensive and definitely worth it.

If you have a cold or flu, you must always deal with used tissues carefully. Don’t leave dirty tissues on your desk or on the floor. Someone else has to pick these up and viruses could be passed on. And finally, remember to cover your nose and mouth when you sneeze!You don’t want to see the small drop of liquids blown out of your nose and mouth when you sneeze, do you? Disgusting, eh? Now you can understand why it’s a good idea to cover your nose and mouth when you sneeze!

小题1: In paragraph 4, we learn that ______.

A.flu injection can cause death

B.most old people die from flu

C.flu is most common in summer

D.flu can kill old people easily小题2:Dealing with used tissues properly is important because ______.

A.it helps keep your classroom tidy

B.people hate picking up dirty tissues

C.it prevents the spread of colds and flu

D.picking up lots of tissues is hard work小题3:Which of the following statements is TRUE according to the passage?

A.Both colds and flu last the same time.

B.Both colds and flu can be prevented by injection.

C.Both colds and flu are caused by the same viruses.

D.Both colds and flu have an aching symptom.小题4:Which is probably the best title for the passage?

A.Cold or Flu?

B.The Different Symptoms of a Cold and Flu

C.Prevention Is Better Than Cure

D.Cover Your Nose and Mouth When Sneezing

多项选择题