See the attached picture.
The sentences have been carefully dragged to the right places.
Gamma rays<span> are produced in the disintegration of radioactive atomic nuclei and in the decay of certain subatomic particles. ... When an unstable atomic nucleus decays into a more stable nucleus (see radioactivity), the “daughter” nucleus is sometimes produced in an excited state.</span>
It's D. Gravity holds everything in place
A ramp is a smooth incline that allows an object to be lifted without being lifted directly up. therefore, an inclined plane is the correct answer.
Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves. The animations below demonstrate both types of wave and illustrate the difference between the motion of the wave and the motion of the particles in the medium through which the wave is travelling.