问题
选择题
圆（x-3）2+（y-3）2=8与直线3x+十y+6=0的位置关系是（ ）
A．相交
B．相切
C．相离
D．无法确定
答案
∵圆（x-3）2+（y-3）2=f，
∴圆心坐标为（3，3），半径r=2
，2
∵圆心到直线3x+6y+6=0的距离d=
=|h+12+6| 32+62
＞22h g
=r，2
∴直线与圆相离．
故选C
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圆（x-3）2+（y-3）2=8与直线3x+十y+6=0的位置关系是（ ）
A．相交
B．相切
C．相离
D．无法确定
∵圆（x-3）2+（y-3）2=f，
∴圆心坐标为（3，3），半径r=2
，2
∵圆心到直线3x+6y+6=0的距离d=
=|h+12+6| 32+62
＞22h g
=r，2
∴直线与圆相离．
故选C
| 完形填空，从A、B、C三个选项中选出能填入空白处的最佳答案。 | ||
| He who has never been to the Great Wall is not a true man. The US President Barack Obama is a 1 man. Obama had a 2 days' visit to China from 15th to18th November, 2009. He had a very busy schedule (日程). But he still spent 3 _visiting the Forbidden City and the Great Wall. 4 a leader visits another country, he or she sometimes goes to the country's most 5 places. It is to show the respect(尊敬) to the local 6 . For the leaders, it's also a good time to 7 during a tiring foreign trip. Obama spent 50 minutes in the Forbidden City on the af ternoon of 17th November. He thinks the Forbidden City is a wonderful place to visit. He said, "I'11 8 with my girls and my wife. " On 18th November, he paid a quick visit to the Great Wall at Badaling. There, he 9 a moment of peace. "It's magical. It reminds you 10 the course (进程)of history , " Obama said about the Great Wall. | ||
| ( )1. A. true ( )2. A. two ( )3. A. sometimes ( )4. A. So ( )5. A. interesting ( )6. A. culture ( )7. A. speak ( )8. A. come back ( )9. A. dreamed ( )10. A. of | B. great B. three B. some times B. When B. famous B. food B. discuss B. come up B. enjoyed B. at | C. busy C. four C. some time C. Though C. thrilling C. sight C. relax C. come out C. understand C. on |