47. A planet orbits a star in an elliptical path under a central gravitational force. The length of the major axis of the ellipse is 5 (in arbitrary units), and the length of the minor axis is 4. The star is located at one focus of the ellipse. What is the ratio of the planet's maximum speed to its minimum speed?
(A) 1:1
(B) 2:1
(C) 3:1
(D) 4:1
(E) 5:1
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統計: A(1), B(1), C(0), D(0), E(0) #3847823
統計: A(1), B(1), C(0), D(0), E(0) #3847823