Answer:
The statements A and D are true
The statements B and C are false
Explanation:
The force between charges can be explained by the Coulomb's Law.
According to Coulomb:
1 - Like charges always repel each other
2- Unlike or opposite charges always attrack each other
3- Force between 2 charges is given by:

where F is the force between 2 charges and r is the distance between 2 charges.
We can see that Force F is inversely proportional to the distance r
Which means that when F increase, r decreases and when F decreases, r increases
the best option would be d.) examples of constructive erosion.
Answer:
Explanation:
A wave is a phenomenon that travels through a material medium without any permanent effect on the medium. It can be classified as mechanical or electromagnetic waves. And the two major types are transverse and longitudinal.
From the given question;
1. Longitudinal waves e.g sound waves, waves in a spring'
2. Frequency (number of cycles per second).
3. Wavelength of the wave. Measured in meters.
4. Transverse waves e.g light waves, water waves.
5. Wave speed.
6. Electromagnetic waves e.g ultraviolet waves, X-rays etc.
7. Amplitude.
8. Hertz.
9. Rarefaction
10. Compression