Erosion is the process where rocks are broken down by natural forces such as wind or water. There are two main types of erosion: chemical and physical
Answer:
Corrective maintenance – costs due to modifying software to correct issues discovered after initial deployment (generally 20% of software maintenance costs)
Adaptive maintenance – costs due to modifying a software solution to allow it to remain effective in a changing business environment (25% of software maintenance costs)
Perfective maintenance – costs due to improving or enhancing a software solution to improve overall performance (generally 5% of software maintenance costs)
Enhancements – costs due to continuing innovations (generally 50% or more of software maintenance costs)
Explanation:
The answer is B. The Doppler Effect is used to calculate the velocity (speed) of something. Astronomers use it to see how fast stars and galaxies are moving away from us.
Hun invasions that triggered a massive migration
