Which statement correctly compares sound and earthquake waves?
sound waves and all earthquake waves have compressions and rarefactions.

sound waves and all earthquakes waves have crests and troughs.

sound waves and some earthquake waves have compressions and rarefactions.

sound waves have crests and troughs and all earthquake waves have compressions and rarefactions.

The answer is: Sound waves and some earthquake waves have compressions and rarefactions.

Rarefaction is the reduction of an item's density, the opposite of compression.

There are three types of mechanical waves: transverse waves, longitudinal waves (sound) and surface waves.

Sound is transmitted as longitudinal waves, also called compression waves.

Seismic waves are fundamentally of two types, compressional, longitudinal waves or transverse waves.

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.