监督分类和非监督分类的结合操作步骤?

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问题:

监督分类和非监督分类的结合操作步骤?

考点:遥感原理与应用遥感原理与应用题库
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关于异丙肾上腺素的描述,正确的是()

A.使肺血管舒张,降低肺动脉压,SVR下降

B.舌下或静脉给药治疗Ⅱ、Ⅲ度房室传导阻滞

C.使骨骼肌血管舒张,舒张压下降,PVR下降

D.使肾、胃肠血管收缩

E.使支气管平滑肌痉挛

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下列说法正确的是[ ]

A.某有机物在足量O2中充分燃烧,生成CO2和H2O的比值为1:1,该有机物的最简式一定为CH2

B.有机物X、Y不论以何种比例混合,只要总物质的量一定,充分燃烧生成CO2和H2O的量也一定,则X与Y中的C、H质量分数一定相同

C.有机物X、Y不论以何种比例混合,只要总质量一定,充分燃烧消耗O2的量也一定,则X、Y可能分别为C2H4、C2H6O

D.能发生银镜反应的物质可能是醛类、羧酸类、酯类,还可能前三者都不是

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室内界面是指().

A.地面

B.墙面

C.栏杆

D.顶面

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BAEP波峰峰间潜伏期测量意义是()

A.Ⅰ~Ⅲ波峰间潜伏期代表低位脑干的传导时间

B.Ⅲ~Ⅴ波峰间潜伏期代表高位脑干的传导时间

C.Ⅰ~Ⅴ峰间潜伏期代表整个脑干听觉通路的传导时间

D.Ⅰ~Ⅲ峰间潜伏期代表听觉传导通路外周段传导时间

E.Ⅰ波峰潜伏期代表听觉传导通路外周段传导时间

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Who is poor in America This is a hard question to answer. Despite poverty’s messiness, we’ve measured progress against it by a single statistic: the federal poverty line. In 2008, the poverty threshold was $ 21,834 for a four-member family with two children under 18. By 1his measure, we haven’t made much progress. Except for recessions, when the poverty rate can rise to 15 percent, it’s stayed in a narrow range for decades. In 2007—the peak of the last business cycle—the poverty rate was 12.5 percent; one out of eight Americans was "poor. " In 1969, another business-cycle peak, the poverty rate was 12.1 percent. But the apparent lack of progress is misleading for two reasons.

First, it ignores immigration. Many immigrants are poor and low skilled. They add to the poor. From 1989 to 2007, about three quarters of the increase in the poverty population occurred among Hispanics—mostly immigrants, their children, and grandchildren. The poverty rate for blacks fell during this period, though it was still much too high (24.5 percent in 2007). Poverty "experts" don’t dwell on immigration, because it implies that more restrictive policies might reduce U.S. poverty.

Second, the poor’s material well-being has improved. The official poverty measure obscures this by counting only pretax cash income and ignoring other sources of support. These include the earned-income tax credit (a rebate to low-income workers), food stamps, health insurance (Medicaid), and housing subsidies. Although many poor live hand to mouth, they’ve participated in rising living standards. In 2005, 91 percent had microwaves, 79 percent air-conditioning, and 48 percent cell phones.

The existing poverty line could be improved by adding some income sources and subtracting some expenses (example: child care). Unfortunately, the administration’s proposal for a "supplemental poverty measure" in 2011—to complement, not replace, the existing poverty line—goes beyond that. The new poverty number would compound public confusion. It also raises questions about whether the statistic is tailored to favor a political agenda.

The "supplemental measure" ties the poverty threshold to what the poorest third of Americans spend on food, housing, clothing, and utilities. The actual threshold not yet calculated—will probably be higher than today’s poverty line. Moreover, this definition has strange consequences. Suppose that all Americans doubled their income tomorrow, and suppose that their spending on food, clothing, housing, and utilities also doubled. That would seem to signify less poverty—but not by the new poverty measure. It wouldn’t decline, because the poverty threshold would go up as spending went up. Many Americans would find this weird., people get richer, but "poverty" stays stuck.

What produces this outcome is a different view of poverty. The present concept is an absolute one: the poverty threshold reflects the amount estimated to meet basic needs. By contrast, the new measure embraces a relative notion of poverty: people are automatically poor if they’re a given distance from the top, even if their incomes are increasing.

Poverty experts are reluctant to talk about immigration because()

A. they may be immigrants or children of immigrants

B. they don’t admit that blacks have improved their life

C. poverty has been reduced through restrictive policies

D. they may be taken as opponents to free immigration policies

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