问题 单项选择题

通过花冠的中心能切出两个以上对称面的花冠称为()。

A.不整齐花冠

B.整齐花冠

C.两侧对称花冠

答案

参考答案:B

问答题

The Environment in Perspective:Is Everything Getting Steadily Worse Much of the discussion of environmental problems in the popular press leaves the reader with the impression that matters have been growing steadily worse, and that pollution is largely a product of the profit system and modern industrialization. There are environmental problems today that are both enormous and pressing, but in fact pollution is nothing new. Medieval cities were pestholes—the streets and rivers were littered with garbage and the air stank of rotting wastes. At the beginning of the eighteenth century, a German traveler reported that to get a view of London from the tower of St. Paul’s, one had to get there very early in the morning "before the air was full of coal smoke." Since 1960 there has been progress in solving some pollution problems, much of it the result of concerted efforts to protect the environment. The quality of the air in most Canadian cities has improved. In Toronto, for example, the concentration of suspended particulates, or soot, in the air has fallen dramatically since 1962. To put this figure in perspective, it should be noted that the current health advisory level for the index is 32. At a level of 58, people with chronic respiratory diseases may be affected. At 100, even healthy people may be affected by prolonged conditions, and those with cardiac and respiratory diseases could suffer severe effects Recently in Toronto, the index has exceeded 32 on fewer than half a dozen days annually. Similar improvements have occurred elsewhere in Canada and in other industrialized countries. Even the famous, or rather infamous, "fogs" of London are almost a thing of the past. There have been two high readings of particular note in the British capital in 1959 (when the index rose to 275 and there was a 10 percent increase over the normal number of deaths) and in 1962 (when the index rose to 575 and there was a 20 percent increase in mortality ). But more recently, London’s, cleaner air has resulted in an astounding 50 percent increase in the number of hours of winter sunshine. In short, pollution problems are not a uniquely modem phenomenon, nor is every part of the environment deteriorating relentlessly. Environmental problems do not occur exclusively in capitalist economies. For example, in the People’s Republic of China, coal soot from factory smokestacks in Beijing envelops the city in a thick black haze. Similarly, smoke from brown-coal furnaces pollutes the air almost everywhere in Eastern Europe. It has been estimated that a third of Poland’s citizens live in areas of "ecological disaster". The citizens of Leipzig, a major industrial city in what was formerly East Germany, have a life expectancy a full six years shorter than the national average. However, we do not mean to suggest that all is well with the environment in market-oriented economies or that there is nothing more to do. While there have been some improvements, serious problems remain. Our world is now subject to a number of new pollutants, most of which are far more dangerous than those we have reduced, even though they may be less visible and less malodorous While environmental problems are neither new nor confined only to capitalist, industrialized economies, these facts are not legitimate grounds for complacency. The potential damage that we are inflicting on ourselves and on our surroundings is very real and very substantial.

单项选择题

在经历了2006年到2007年的持续高速上涨,经历了国家出台的数项严厉的宏观调控政策,特别是货币紧缩政策之后,2008年一季度的房地产市场表现显得格外重要。
2008年4月2日,国家发改委公布的数据显示,截至3月20日,3月份全国36个大中城市住房价格总体回落。4月16日,国家统计局发布的数据显示,今年前3个月70个大中城市住房价格同比涨幅分别为11.3%、10.90%、10.7%,涨幅小幅回落。中国人民银行3月20日发布的一季度全国城镇储户问卷调查显示,房地产市场观望气氛浓厚,居民购房意愿再创新低,未来三个月打算购房的居民占比为14.6%,分别比上季度和上年同期降低1.3和1.9个百分点,并创调查以来最低水平。北京、上海、广州等七大城市居民购房意愿全线下跌,其中上海跌幅最大,比上季度下跌4.3个百分点,广州次之,跌3.8个百分点。
数据佐证着这样一个事实:2008年一季度的房地产市场预期发生了某种变化,并因此改变了以往的单边上扬行情。
权威部门的数据显示,房价涨幅确有放缓,部分一线城市下降。国家发改委4月22日发布的报告显示,前3个月,全国70个大中城市新建住房销售价格环比涨幅分别为0.3%、0.2%和0.3%,明显低于去年月均1.0%的涨幅。其中,3月份有13个城市为负增长,环比价格下降最大的城市深圳,为-4.9%。可以参照的一个数据是深圳市国土房产局发布的《2008年一季度深圳房地产市场发展分析报告》,称一季度深圳住宅均价呈大幅下挫走势。其中,3月份的房价环比降幅达到了16.53%,为13618.42元/平方米。这个价格已经回到了2007年4-5月间的价格水平。
有关专家分析,一季度70个大中城市房屋销售价格同比上涨11.0%,比上年同期高5.4个百分点。对于这一数据,应该考虑到的一个实际情况是,由于去年一季度并不是全年房价的峰值,3月份以及一季度房价与2007年峰值比应该不是上涨而是下降。

2008年3月深圳住宅均价环比下降( )

A.4.9%
B.16.53%
C.0.3%
D.6.7%