- 牛顿运动定律
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下列说法正确的是
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下列说法正确的是
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下面关于物体惯性大小的说法中,正确的是
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下列说法中正确的是
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下列说法正确的是
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一汽车关闭发动机后在路面情况相同的公路上直线滑行,下面关于车速、惯性、质量和滑行路程的讨论,正确的是
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正确答案
几个共点力作用在一个物体上,使物体处于平衡状态,下列说法正确的是( )
①几个力的合力一定为零,各个力在任意方向上分力的合力也为零
②合力一定为零,但F=故FX、Fy不一定为零
③其中任意一个力的大小一定与其它几个力的合力大小相等,而方向相反
④只改变一个力的大小或方向,物体的状态可能不变.
正确答案
两木块A、B由同种材料制成,mA>mB,并随木板一起以相同速度向右匀速运动,如图所示,设木板足够长,当木板突然停止运动后,则( )
正确答案
火车在水平的长直轨道上匀速运动,门窗紧密的车厢里有一位旅客向上跳起,结果仍然落在车厢地板上的原处,原因是
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关于物体的惯性,下述说法中正确的是
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正确答案
月球表面上的重力加速度为地球表面上的重力加速度的,同一个飞行器在月球表面上时与在地球表面上时相比较( )
正确答案
在现行建设工程造价构成中,工程监理费属于______。
A.预备费
B.与建设项目相关的其他费用
C.建筑安装工程投资中的间接费
D.与未来企业生产经营有关的其他费用
正确答案
B
解析
暂无解析
如果甲产品和乙产品的需求交叉弹性系数是负数,则说明甲产品和乙产品( )。
A.无关
B.是替代品
C.是互补品
D.是缺乏价格弹性的
正确答案
C
解析
[解析] 需求交叉价格弹性是指一种商品价格的相对变化与由此引起的另一种商品需求量相对变动之间的比率。需求交叉弹性系数Eij>0,两种商品为替代品;需求交叉弹性系数 Eij<0,两种商品为互补品。
Every spring migrating salmon return to British Columbia’s rivers to spawn. And every spring new reports detail fresh disasters that befall them. This year is no different. The fisheries committee of Canada’s House of Commons and a former chief justice of British Columbia, Bryan Williams, have just examined separately why 1.3 million sockeye salmon mysteriously "disappeared" from the famed Fraser river fishery in 2004.Their conclusions point to a politically explosive conflict between the survival of salmon and the rights of First Nations, as Canadians call Indians.
In 2004, only about 524, 000 salmon are thought to have returned to the spawning grounds, barely more than a quarter the number who made it four years earlier. High water temperatures may have killed many. The House of Commons also lambasted the federal Department of Fisheries and Oceans (DFO) for poor scientific data, and for failing to enforce catch levels. Four similar reports since 1992 have called for the department’s reform. In vain: its senior officials are "in denial" about its ’failings, said the committee.
Mr. Williams’ report added a more shocking twist. He concluded that illegal fishing on the Fraser river is "rampant and out of control", with "no go" zones where fisheries officers are told not to confront Indian poachers for fear of violence. The judge complained that the DFO withheld a report by one of its investigators which detailed extensive poaching and sale of salmon by members of the Cheam First Nation, some of whom were armed.
Some First Nations claim an unrestricted right to fish and sell their catch. Canada’s constitution acknowledges the aboriginal right to fish for food and for social and ceremonial needs, but not a general commercial right. On the Fraser, however, the DFO has granted Indians a special commercial fishery. To some Indians, even that is not enough.
Both reports called for more funds for the DFO, to improve data collection and enforcement. They also recommended returning to a single legal regime for commercial fishing applying to all Canadians.
On April 14th, Geoff Regan, the federal fisheries minister, responded to two previous reports from a year ago. One, from a First Nations group, suggested giving natives a rising share of the catch. The other proposed a new quota system for fishing licences, and the conclusion of long-standing talks on treaties, including fishing rights, with First Nations. Mr. Regan said his department would spend this year consulting "stakeholders" (natives, commercial and sport fishermen). It will also launch pilot projects aimed at improving conservation, enforcement and First Nations’ access to fisheries.The "explosive conflict" in the first paragraph refers to()
A.salmon's return to British Columbia's rivers to spawn.
B.the fisheries committee of Canada's House of Commons and Bryan Williams.
C.the struggle between sockeye salmon and human beings.
D.the collision between salmon's survival and human fishery.
正确答案
D
解析
细节题。文章第一段最后一句提到“他们的结论指向鲑鱼的生存和第一民族的权利之间的一种政治性的强烈冲突”,也就是说,“强烈的冲突”指的是鲑鱼的生存和人类的捕捞之间的冲突,所以[D]符合文意。[A]“鲑鱼返回英国哥伦比亚的河流产卵”,[B]“加拿大众议院的渔业委员会和Bryan Williams”,[C]“红大马哈鱼和人类之间的竞争”都与文章意思不符。
关于惯性,以下说法正确的是( )
正确答案
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