题干

我国是一个统一的多民族国家,各民族相互融合,取长补短,共同发展。下列有关少数民族与汉族的关系说法不正确的一项是(  )

A:西汉时新疆地区开始接受中央管辖

B:唐朝时吐蕃与唐和亲,汉藏“和同为一家”

C:明朝时出现了新的民族──回族

D:清朝设置驻藏大臣加强了对西藏的管辖

上一题 下一题 0.0难度 选择题 更新时间:2018-03-16 03:04:34

答案(点此获取答案解析)

C

同类题2

阅读理解

    It may be hard to believe, but the American Revolution(革命)—the war that freed the American states from British control—began over a cup of tea. Tea was not the only thing that caused the war, of course, but it played a very big part.

    The British people's love of tea is well-known. When the British won control over mush of North America in the early 1700s, they brought their tea- drinking habits with them. Tea quickly became the continents most popular drink. As tea could not be grown locally, just as in Britain, it was shipped into the country—mostly from India.

In the early 1700s, the Britain government made a special deal with the East India Company, as an English trading company. They agreed that no other company was allowed to bring tea to Britain or any country controlled by Britain, including America. It was a great deal for the East India Company, since it meant that the company could decide whatever price it wanted for its products. And it always decided on a high price!

In North America, the local people did not like having to pay such high prices. Instead of overpaying for tea from the British, they turned to Dutch traders, who secretly brought tea to the country that was just as good—and much less expensive. Although this broke the law, the American people didn't care. They got the same cup of tea at a much lower price.

The East India Company, however, didn't like this at all. By the 1760s, they were losing millions of pounds each year to Dutch traders—a huge amount of money in a time when £60 a year was considered a good income. Instead of reducing their prices to compete with the Dutch, the company asked the British government for help and the government agreed.

    In 1767, the British introduced new law that increased the prices of all goods which were brought into America. These laws helped make the East India Company even richer and forced local people to pay much more for everything. The American leaders asked the British government not to do so, but the British refused to listen. These unfair laws increased Americans' anger about British rule and the rest, as they say, is history.

同类题3

科学研究源于观察和问题,拓展性小组同学观察到下列现象,跳伞运动员在未打开降落伞时下落很快,打开降落伞下落的速度会减小;“瓢泼大雨”以很快速度降落到地面,而“毛毛细雨”则缓慢地飘落到地面.

【查阅资料】物体从高空下落时,速度越来越大,所受阻力也越来越大,当阻力增大到重力相等时,将以某一速度作匀速直线运动,这个速度被称为物体下落的收尾速度.

【提出猜想】物体从高空下落时收尾速度与什么因素有关?

【建立猜想】①可能与物体的横截面积有关.②可能与物体的____有关.

【设计方案】同学们经过讨论后认为,可以用小球作为理想化模型来代替生活中的不规则问题作为研究对象进行探究,于是同学们决定取5个不同的小球进行实验,在相同环境条件下,分别从一定高度(足够高)由静止下落,来探究小球从高空下落时的收尾速度与哪些因素有关.

【获取证据】相关测量数据见表:

 小球编号

 1

 2

 3

 4

 5

 小球质量m(g)

 2

 5

 5

 5

 45

 小球半径r(m)

 0.05

 0.05

 0.10

 0.25

 0.15

小球的收尾速度v(m/s)

 16

 40

 10

 1.6

【得出结论】

①比较1、2号小球的相关实验数据,可以得到的结论是____

②根据表中数据,推测5号小球的收尾速度v=____m/s.

③请你结合上述探究,解释“跳伞运动员打开降落伞后比打开降落伞前收尾速度小”的原因是____