Which three applications use technologies that apply the Doppler effect? A.
Air-traffic control
B.
Weather forecasting
C.
Building inspection
D.
Pest control

A, B & C are correct.

Explanation:

In physics, Doppler effect is a term used to describe the change in frequency of a wave during the relative motion existing between the source of the wave the person acting a the observer.

Looking at the options given, this Doppler effect is applicable to: air traffic control where traffic controllers attempt to direct the traffic on the ground; weather forecasting where the conditions of the atmosphere at a particular time and place is being predicted; and in building inspection where we can use a non destructive test equipment known as Schmidt hammer to career out min destructive tests on a building.

the first, second, and fifth options