搜题请搜索小程序“爱下问搜题”
问题 选择题

茶叶治疗脚气的丝状菌特别有效，是因为茶叶中含有一种叫单宁酸的物质．所以患脚气的人，每晚将茶叶煮成浓汁来洗脚，日久便会不药而愈．单宁酸的化学式为C76H52O46，下列有关说法正确的是（　　）

A．单宁酸是一种氧化物

B．茶叶由碳、氢、氧三种元素组成

C．单宁酸由碳、氢、氧3个原子构成

D．单宁酸分子中碳、氢、氧原子个数比为38：26：23

答案

A、氧化物含有两种元素而单宁酸有三种元素，故此选项错误．

B、茶叶中的物质很多单宁酸只是其中的一种，故此选项错误．

C、单宁酸由分子构成不是原子构成，故此选项错误．

D、单宁酸化学式既是其分子式，其分子中含有的原子数既是其右下角数值，则原子个数比是38：26：23，故此选项正确．

故选D

判断题

我国社会主义法一般具有溯及力，但法律另有规定的除外。 ( )
查看答案
问答题

In future, as newspaper fade and change, will politicians therefore burgle their opponents’ offices without punishment Journalism schools and think-tanks, especially in America, are worried about the effect of a collapsing journalism.
Nobody should enjoy the disappearance of once-great newspapers. But the decline of newspapers will not be as harmful to society as some fear. 46. Denmocracy, remember, has already survived the huge television-led decline in circulation since the 1950s. It has survived as readers have evaded papers and papers have evaded what was in conservative times thought of as serious news. And it will surely survive the decline to come.
47. A few papers that invest in investigative stories which often benefit society the inost are in a good position to survive, as long as their owners do a comnpetent job of adjusting to changing circumstances. Publications like the New York Times and the Wall Street Journal should be able to put up the price of their journalism to compensate for advertising revenues lost to the internet—especially as they cater to a more global readership. 48. As with many industries, it is those in the middle—neither highbrow, nor entertainingly populist—that are likeliest to fall by the wayside.
49. The usefulness of the press goes much wider than investigating abuses or even spreading general news; it lies in holding governments to account--trying them in the court of public opinion. The internet has expanded this court. Anyone looking for information has never been better equipped. People no longer have to trust a handful of national papers or, worse, their local city paper. News-aggre-gation sites such as Google News draw together sources from around the world. The website of Britain’s Guardian now has nearly half as many readers in America as it does at home.
50. Furthermore, a new force of "citizen" journalists is itc.hing to hold politicians to account. The web has opened the closed world of professional editors and reporters to anyone with a keyboard and an internet connection. Several companies have been chastened by amateur postings—of flames erupting from Dell’s laptops or of cable TV repairmen asleep on the sofa. Each blogger is capable of bias and slander, but, taken as a group, bloggers offer the searcher after truth boundless material to chew over. Of course, the internet panders to closed minds; but so has much of the press.
查看答案