When a sound from a source is refracted away from the surface of the earth, it gives an indication that the
a. air is cooler than the ground.
b. ground is cooling faster than the air.
c. air has high humidity.
d. wind is blowing in the direction of the sound.

The correct answer is A. air is cooler than the ground.

All of the other possible solutions would not cause refraction of sounds away from the surface, some of it would not influence the sound in any way. Sound waves travel slower through cool air and sometimes they disappear before even reaching the ground.

Joe ran 130 yards because 3 feet make 1 yard so using this ratio 390 feet make 130 yards.

Check -it can you examine advantages and drawbacks to possible solutions.check-it can you consider options to solve a problem.check-it can you persuade an audience to support a proposal.check-it can you identify the cause of a problem.