[题目]已知圆C1:(x+1)2+(y-3)2＝25.圆C2与圆C1关于点(2,1)对称.则圆C2的方程是 . 题目和参考答案——青夏教育精英家教网—

题目内容

【题目】已知圆C1：（x＋1）2＋（y－3）2＝25，圆C2与圆C1关于点（2,1）对称，则圆C2的方程是______________________.

【答案】（x－5）2＋（y＋1）2＝25

【解析】设⊙C2上任意一点P（x，y），它关于（2,1）的对称点（4－x,2－y）在⊙C1上，∴（x－5）2＋（y＋1）2＝25.

练习册系列答案

相关题目

【题目】下列各组词语中，没有错别字的一组是

A．横七竖八蠕动儒子牛蜂涌而至

B．生死由天嘈杂执拗不假思索

C．血肉之驱见机反射生杀予夺

D．步履蹒跚声吟欧打草煎人命

【题目】下列各句中，没有错别字的一项是

A．巨型运载火箭喷射出一团橘红色的烈焰，托举着载人飞船拨地而起，直刺九宵……

B．它意味着中国人“摘星览月”已为期不远了。

C．特别是“神舟”三号、四号在全载人状态下连续发射成功，表志着中国已具备了把自己的航天员送上太空的能力。

D．2003年9时10分许，飞天勇士杨利伟乘坐载人飞船顺利进入太空。一个民族迎来了飞天梦圆的辉煌时刻。

【题目】

根据短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Urbanization

Until relatively recently, the vast majority of human beings lived and died without ever seeing a city. The first city was probably founded no more than 5,500 years ago. 【1】. In fact, nearly everyone lived on farms or in tiny rural (乡村的) villages. It was not until the 20th century that Great Britain became the first urban society in history--- a society in which the majority of people live in cities and do not farm for a living.

Britain was only the beginning. 【2】 .The process of urbanization ——the migration (迁移) of people from the countryside to the city--- was the result of modernization, which has rapidly transformed how people live and where they live.

In 1990, fewer than 40% of Americans lived in urban areas. Today, over 82% of Americans live in cities. Only about 2% live on farms. 【3】 .

Large cities were impossible until agriculture became industrialized. Even in advanced agricultural societies. It took about ninety-five people on farms to feed five people in cities. 【4】 . Until modern times, those living in cities were mainly the ruling elite(精英) and the servants, laborers and professionals who served them. Cities survived by taxing farmers and were limited in size by the amount of surplus food that the rural population produced and by the ability to move this surplus from farm to city.

Over the past two centuries, the Industrial Revolution has broken this balance between the city and the country. 【5】 . Today, instead of needing ninety-five farmers to feed five city people, one American farmer is able to feed more than a hundred non-farmers.

A. That kept cities very small.

B. The rest live in small towns.

C. The effects of urban living on people should be considered.

D. Soon many other industrial nations become urban societies.

E. But even 200 years ago, only a few people could live in cities.

F. Modernization drew people to the cities and made farmers more productive.

G. Modern cities have destroyed social relations and the health of human beings.

【题目】下列句子中加横线的词的解释，不正确的一项是( )

A．河内凶，则移其民于河东凶：收成不好，荒年

B．谷与鱼鳖不可胜食胜：尽

C．养生丧死无憾憾：遗憾，不满

D．斯天下之民至焉斯：这样

【题目】下列各句中，画线的成语使用不恰当的一句是

A．在地方“专升本”的诸多利益诉求与冲动下，一些老牌高等专科学校改头换面加入综合性大学的群体，成为一批“四不像”大学。

B．全球资本市场已有好转迹象，世界经济不像半年前那样陷于如履薄冰的危险境地，但是，今年的预期增幅不会较去年大幅上升。

C．近日，提高语文作为母语学科重要地位的有关高考改革的言论，在母语教学被忽视的当下，真可谓空谷足音。

D．美国“监控门”事件触发的新风波不断升级，越来越多的国家开始抨击美国，其中不乏铁杆盟友，令美国左支右绌，理屈词穷。

【题目】

I felt when the girl refused my kind offer.

A. hurt

B. destroyed

C. ruined

D．damaged

【题目】下列词语中没有错别字的一组是

A．姿态赏玩即使黄城人海

B．细腻清闲啼唱尘沙灰土

C．囚系幽囚剪揖偃苗助长

D．攀援绿州开释烽烟四逼

【题目】仿照下面的示例，自选话题，另写三句话，要求使用比喻的修辞手法，句式与示例相同。

故乡是一头老牛，蹲在父亲老眼昏花的目光里；

故乡是一朵山菊，开在母亲饱经沧桑的皱纹里；

故乡是一首乡曲，响在牧童清脆嘹亮的柳笛里。

____________________________________________________________________

试题分类