Why is a bird able to sit on a power line? a. because the line is covered with insulating material. c. the voltage in power lines is very small. b. because both feet are on the same line there is no difference in voltage from foot to foot. d. birds are not good conductors of electricity

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.