What is true about exercise in the modern era? A. Only middle-aged people lift weights. B. Fitness, ability, and the desire to participate matter most. C. There is an age limit to most sports. D. Marathons are only open to people in their 20s and 30s.

Currents in dc transmission lines can be 100 a or higher. some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. for a line that has current 150 a and a height of 8.0 m above the ground, what magnetic field does the line produce at ground level? express your answer in teslas and as a percentage of the earth’s magnetic field, which is 0.50 g. is this value cause for worry?