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(2002•武汉)已知Rt△ABC中,∠C=90°,O为斜边AB上的一点,以O为...
(2002•武汉)已知Rt△ABC中,∠C=90°,O为斜边AB上的一点,以O为圆心的圆与边AC,BC分别相切于点E,F,若AC=1,BC=3,则⊙O的半径为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232602462630448/SYS201310212326024626304011_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232602462630448/SYS201310212326024626304011_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232602462630448/SYS201310212326024626304011_ST/2.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021232602462630448/SYS201310212326024626304011_ST/3.png)
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