问题 选择题

你有过这样的体验吗?当你不断的用力向气球里吹气,吹一段时间后会感到头晕,其原因是(   )

A.吹气过长,吸气短促,呼吸过程失调

B.呼吸及运动频繁,使呼吸中枢疲劳

C.吹气过长、吸气短促,造成大脑缺氧

D.呼吸及运动频繁,使呼吸中枢兴奋

答案

答案:C

题目分析:吹气相当于呼吸作用的呼气过程,当人不断的用力向气球里吹气,吹气时间长,相当于呼气的时间长,相比吸气的时间短,人体获得的氧气少,导致大脑缺氧,人体会感到头晕。选项C符合题意。

问答题
单项选择题

This is offered as a textbook illustration of the principle that voters are far shrewder than most politicians believe. This case study highlighting Washington’’s inability to fool anyone is based on a recent survey of the attitudes of people on Medicare about their new prescription-drug benefit.Last fall, when Congress added prescription-drug coverage to Medicare, the new law was hailed as a political masterpiece. Congressional Democrats, who overwhelmingly opposed the bill, thundered that they, too, were eager to provide a drug benefit under Medicare, but they championed alternative legislation that offered a larger drug subsidy and smaller incentives to health insurers to participate. Liberals such as Sen. Edward Kennedy were confident that the drug bill, with plenty of holes in its benefit formulas, would inevitably be expanded around the time it took effect.Not many in Congress seemed troubled that the federal budget was deep in deficit, the nation was saddled with future expenditures for the Iraq war and virtually no health care expert believed that the legislation would fit into its projected $400-billion-over-10-years cost framework. The new law was a cynical bargain that had more to do with the 2004 election than a rational approach to the prescription-drug needs of the nation’’s elderly.The prescription-drug legislation seems a compromise between competing ideologies inserted into a fixed congressional budget. Put another way, it was sausage-stuffing in the guise of lawmaking. And, what no one anticipated was the reaction of the elderly, a group that votes in disproportionate numbers.

Democratic Congressmen suggested that the government should________.

A.be enthusiastic in providing a drug benefit to the people

B.oppose the new legislation with thundering protests

C.give more money, so to speak, to medicine makers and retailers

D.provide financial assistance to people wanting to buy life insurance