1. A straight line" between two points on a sphere is defined to be an arc of the great circle passing through these points. Given two points on the equator on the Earth (considered as a perfect sphere), one at longitude 0 degree and the other at longitude 180 degrees, the number of straight lines" passing through these two points is (A) 1. (B) 2. (C) 4. (D) infinite.

1. A straight line" between two points on a sphere is defined to be an

1.	1. A straight line" between two points on a sphere is defined to be an arc of the great circle passing through these points. Given two points on the equator on the Earth (considered as a perfect sphere), one at longitude 0 degree and the other at longitude 180 degrees, the number of straight lines" passing through these two points is (A) 1. (B) 2. (C) 4. (D) infinite.
Answer» 1. A straight line" between two points on a sphere is defined to be an arc of the great circle passing through these points. Given two points on the equator on the Earth (considered as a perfect sphere), one at longitude 0 degree and the other at longitude 180 degrees, the number of straight lines" passing through these two points is (A) 1. (B) 2. (C) 4. (D) infinite.