Does the doppler effect occur for only some types of waves or all types of waves

Ahill is made of rock particles of different sizes. which of these agents of erosion probably caused the hill to form?

Simple astronomical telescope the objective lens has a focal length of 75 cm and that of a piece of 5cm of the lenses are 18 cm apart when will be final image of a distant object before

Which question did the author of how to grow a school garden consider about the audience before writing the project plan