1/5单选题
难度：
1.如图，已知⊙O的半径为10，弦AB=12，M是AB上任意一点，则线段OM的长可能是（ ）
| A | 5 |
| B | 7 |
| C | 9 |
| D | 11 |
- 提示1：
- 55Sx6aKY5oSP55+l77yMT03nmoTmnIDlpKflgLzmmK8xMO+8jOW8pkFC55qE5bym5b+D6Led5pivT03nmoTmnIDlsI/lgLzvvIzliKnnlKjlnoLlvoTlrprnkIblkozli77ogqHlrprnkIbvvIzlj6/msYLlh7pPTeeahOacgOWwj+WAvOS4ujjvvIzlm6DogIznrZTmoYjkuK3lj6rmnIk556ym5ZCI5p2h5Lu277yO
正确答案：Qw==
PGltZyB3aWR0aD0xMDAgaGVpZ2h0PTEwMCBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzdCLzAxL3JCQUNKMVZpbDVHejhzcEtBQUFJYkJrOVlsczg4NC5wbmciID7op6PvvJrov4fngrlP5L2cT03iiqVBQu+8jOWegui2s+S4uk08YnI+4oi1T03iiqVBQu+8jEFCPTEyPGJyPuKItEFNPUJNPTY8YnI+5ZyoUnTilrNPQU3kuK3vvIxPTT08aW1nIHdpZHRoPTIxMCBoZWlnaHQ9MTYgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC9CMC83MS9yQkFDRTFWaWw1R1I3Q0RDQUFBSWI4VHVpSnM4NzAucG5nIiBhbHQ95pWw5a2m5YWs5byPPjxicj7miYDku6U44omkT03iiaQxMDxicj7mlYXlupTpgIlD77yO
2/5单选题
难度：
2.如图，AB是⊙O直径，弦CD⊥AB于点E．若CD=8，OE=3，则⊙O的直径为()
| A | 5 |
| B | 6 |
| C | 8 |
| D | 10 |
- 提示1：
- 6L+e5o6lT0PvvIznlLHlnoLlvoTlrprnkIblj6/lvpfliLBDReeahOmVvw==
- 提示2：
- 6L+b6ICM5Y+v5ZyoUnTilrNPQ0XkuK3vvIzmsYLlh7riiplP55qE5Y2K5b6E77yM6L+b6ICM5Y+v5b6X5Yiw4oqZT+eahOebtOW+hO+8jg==
正确答案：RA==
6Kej77ya6L+e5o6lT0PvvJs8YnI+5ZyoUnTilrNPQ0XkuK3vvIznlLHlnoLlvoTlrprnkIbnn6VDRT1ERT0077yMPGJyPueUseWLvuiCoeWumueQhuW+l++8mjxicj5PQzxzdXA+Mjwvc3VwPj1PRTxzdXA+Mjwvc3VwPitDRTxzdXA+Mjwvc3VwPj0zPHN1cD4yPC9zdXA+KzQ8c3VwPjI8L3N1cD49NTxzdXA+Mjwvc3VwPu+8jOWNs09DPTXvvIw8YnI+5omA5Lul4oqZT+eahOebtOW+hOS4ujEw77yMPGJyPuaVhemAiUTvvI48YnI+PGltZyB3aWR0aD0xMzEgaGVpZ2h0PTEzNCBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwL0IwLzcxL3JCQUNFMVZpbDVid2ZBTUJBQUFNeFhhMzNFUTE1OS5wbmciPg==
3/5单选题
难度：
3.一条排水管的截面如图所示．已知排水管的截面圆半径OB=10，截面圆圆心O到水面的距离OC是6，则水面宽AB是（）
| A | 16 |
| B | 10 |
| C | 8 |
| D | 6 |
- 提示1：
- 5YWI5qC55o2u5Z6C5b6E5a6a55CG5b6X5Ye6QUI9MkJD77yM5YaN5qC55o2u5Yu+6IKh5a6a55CG5rGC5Ye6QkPnmoTplb/vvIzov5vogIzlj6/lvpflh7rnrZTmoYjvvI4=
正确答案：QQ==
6Kej77ya4oi15oiq6Z2i5ZyG5ZyG5b+DT+WIsOawtOmdoueahOi3neemu09D5pivNu+8jDxicj7iiLRPQ+KKpUFC77yMPGJyPuKItEFCPTJCQ++8jDxicj7lnKhSdOKWs0JPQ+S4re+8jE9CPTEw77yMT0M9Nu+8jOeUseWLvuiCoeWumueQhuW+lzxicj7iiLRCQz0477yMPGJyPuKItEFCPTJCQz0yw5c4PTE277yOPGJyPuaVhemAiUHvvI4=
4/5单选题
难度：
4.
如图，两正方形彼此相邻且内接于半圆，若小正方形的面积为16cm2，则该半圆的半径为（ ）
| A | (4+ |
| B | 9cm |
| C | 4 |
| D | 6 |
)
- 提示1：
- PHA+6L+e5o6lT0HjgIFPQuOAgU9F77yM6K+BUnTilrNBRE/iiYxSdOKWs0JDT++8jOaOqOWHuk9EPU9DPC9wPg==
- 提示2：
- 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
- 提示3：
- PHA+5rGC5Ye6RUY9RkM9NGNtPC9wPg==
- 提示4：
- PHA+5Zyo4pazT0ZF5Lit55Sx5Yu+6IKh5a6a55CG5rGC5Ye6Ye+8jOWNs+WPr+axguWHuuetlOahiO+8jjwvcD4=
正确答案：Qw==
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
5/5单选题
难度：
5.某公园中央地上有一个大理石球，小明想测量球的半径，于是找了两块厚10cm的砖塞在球的两侧（如图所示），他量了下两砖之间的距离刚好是60cm，聪明的你算一下这个大石球的半径（ ）
| A | 40cm |
| B | 30cm |
| C | 20cm |
| D | 50cm |
- 提示1：
- 5qC55o2u6aKY5oSP5Y+v55+l77yM5Lik56CW5LmL6Ze055qE6Led56a75q2j5aW95piv5ZyG5Lit5bym55qE6Led56a777yM56CW55qE5Y6a5bqm5piv5oux6auY
- 提示2：
- 5qC55o2u5Yu+6IKh5a6a55CG5ZKM5Z6C5b6E5a6a55CG5Y+v5Lul5rGC5Ye65ZyG55qE5Y2K5b6E77yO
正确答案：RA==
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